diff --git a/Win32-services.cabal b/Win32-services.cabal
--- a/Win32-services.cabal
+++ b/Win32-services.cabal
@@ -1,113 +1,145 @@
-name:           Win32-services
-category:       System
-version:        0.1
-cabal-version:  >= 1.14
-build-type:     Simple
-author:         Michael Steele
-maintainer:     Michael Steele <mikesteele81@gmail.com>
-copyright:      Copyright (C) 2011-2013 Michael Steele
-homepage:       http://github.com/mikesteele81/win32-services
-bug-reports:    http://github.com/mikesteele81/win32-services/issues
-license:        BSD3
-license-file:   LICENSE
-tested-with:    GHC == 7.4.2
-stability:      provisional
-synopsis:       Windows service applications
-description:
-  This package provides a partial binding to the Win32 System Services
-  API. It's now possible to write Windows service applications using
-  Haskell.
-  .
-  The binding is partial. Here are a few ways in which it differs from the
-  official API:
-  .
-  * Only services running within their own process are supported. These are
-  processes of the 'WIN32_OWN_PROCESS' type.
-  .
-  * In cases where multiple versions of the same function exist (for
-  compatibility), this binding only offers one of them.
-  .
-  * None of the extended control codes are supported. Handlers you write will
-  automatically report this to the operating system when such controls are
-  received.
-  .
-  * Only facilities for writing services are supported; not controlling them.
-  .
-  Effort has been made to simplify using the API without hiding what is
-  happening behind the scenes. Users are encouraged to read Microsoft's
-  documentation under 'Dev Center - Desktop > Docs > Desktop app development
-  documentation > System Services > Services'. The official example has been
-  ported to Haskell. This can be found in the 'examples' directory of the
-  source tree.
-  .
-  /Simple Example and Usage/
-  .
-  @
-  module Main where
-  .
-  import Control.Concurrent.MVar
-  import System.Win32.SystemServices.Services
-  .
-  main = startServiceCtrlDispatcher \"Test\" $ \name _ -> do
-  &#x20;   mStop <- newEmptyMVar
-  &#x20;   hStatus <- registerServiceCtrlHandlerEx name $ handler mStop
-  &#x20;   setServiceStatus hStatus running
-  &#x20;   takeMVar mStop
-  &#x20;   setServiceStatus hStatus stopped
-  .
-  handler mStop hStatus STOP = do
-  &#x20;   setServiceStatus hStatus stopPending
-  &#x20;   putMVar mStop ()
-  &#x20;   return True
-  handler _ _ INTERROGATE = return True
-  handler _ _ _           = return False
-  .
-  stopped = SERVICE_STATUS WIN32_OWN_PROCESS STOPPED [] nO_ERROR 0 0 0
-  stopPending = stopped &#x7b; currentState = STOP_PENDING
-  &#x20;                     , waitHint = 3000 &#x7d;
-  running = stopped &#x7b; currentState = RUNNING
-  &#x20;                 , controlsAccepted = [ACCEPT_STOP] &#x7d;
-  @
-  .
-  @
-  C:\programming\test\>ghc --make -threaded Main.hs
-  [1 of 1] Compiling Main             ( Main.hs, Main.o )
-  Linking Main.exe ...
-  \<linker warnings omitted\>
-  C:\\programming\\test\>copy Main.exe c:\\svc\\Test.exe
-      1 file(s) copied.
-  @
-  .
-  Execute the following from an elevated command prompt to register the
-  service:
-  .
-  @
-  C:\\svc\>sc create Test binPath= c:\\svc\\Test.exe
-  [SC] CreateService SUCCESS
-  @
-  .
-  The service can now be started and stopped from the services console.
-
-extra-source-files: examples/*.hs
-
-source-repository head
-  type: git
-  location: git://github.com/mikesteele81/win32-services.git
-
-library
-  build-depends: base             >= 4.5 && < 4.6
-               , errors
-               , Win32
-  default-language: Haskell2010
-  ghc-options:     -Wall
-  hs-source-dirs: src
-  Exposed-Modules: System.Win32.SystemServices.Services
-  Extra-Libraries: Advapi32
-  other-modules: System.Win32.SystemServices.Services.SERVICE_STATUS
-               , System.Win32.SystemServices.Services.Raw
-               , System.Win32.SystemServices.Services.SERVICE_TABLE_ENTRY
-               , System.Win32.SystemServices.Services.Types
-               , System.Win32.SystemServices.Services.SERVICE_ACCEPT
-               , System.Win32.SystemServices.Services.SERVICE_CONTROL
-               , System.Win32.SystemServices.Services.SERVICE_STATE
-               , System.Win32.SystemServices.Services.SERVICE_TYPE
+name:           Win32-services
+category:       System
+version:        0.2
+cabal-version:  >= 1.14
+build-type:     Simple
+author:         Michael Steele
+maintainer:     Michael Steele <mikesteele81@gmail.com>
+copyright:      Copyright (C) 2011-2013 Michael Steele
+homepage:       http://github.com/mikesteele81/win32-services
+bug-reports:    http://github.com/mikesteele81/win32-services/issues
+license:        BSD3
+license-file:   LICENSE
+tested-with:    GHC == 7.4.2
+stability:      provisional
+synopsis:       Windows service applications
+description:
+  This package provides a partial binding to the Win32 System Services
+  API. It's now possible to write Windows service applications using
+  Haskell.
+  .
+  The binding is partial. Here are a few ways in which it differs from the
+  official API:
+  .
+  * Only services running within their own process are supported. These are
+  processes of the 'WIN32_OWN_PROCESS' type.
+  .
+  * In cases where multiple versions of the same function exist (for
+  compatibility), this binding only offers one of them.
+  .
+  * None of the extended control codes are supported. Handlers you write will
+  automatically report this to the operating system when such controls are
+  received.
+  .
+  * Only facilities for writing services are supported; not controlling them.
+  .
+  Effort has been made to simplify using the API without hiding what is
+  happening behind the scenes. Users are encouraged to read Microsoft's
+  documentation under 'Dev Center - Desktop > Docs > Desktop app development
+  documentation > System Services > Services'. The official example has been
+  ported to Haskell. This can be found in the 'examples' directory of the
+  source tree.
+  .
+  /Simple Example and Usage/
+  .
+  @
+  module Main where
+  .
+  import Control.Concurrent.MVar
+  import System.Win32.SystemServices.Services
+  .
+  main = do
+  &#x20;   mStop <- newEmptyMVar
+  &#x20;   startServiceCtrlDispatcher \"Test\" 3000 (handler mStop) $ \\_ _ h -> do
+  &#x20;       setServiceStatus h running
+  &#x20;       takeMVar mStop
+  .
+  handler mStop hStatus STOP = do
+  &#x20;   setServiceStatus hStatus stopPending
+  &#x20;   putMVar mStop ()
+  &#x20;   return True
+  handler _ _ INTERROGATE = return True
+  handler _ _ _           = return False
+  .
+  running = SERVICE_STATUS WIN32_OWN_PROCESS RUNNING [ACCEPT_STOP] nO_ERROR 0 0 0
+  stopPending = running &#x7b; currentState = STOP_PENDING
+  &#x20;                     , controlsAccepted = []
+  &#x20;                     , waitHint = 3000 &#x7d;
+  @
+  .
+  @
+  C:\programming\test\>ghc --make -threaded Main.hs
+  [1 of 1] Compiling Main             ( Main.hs, Main.o )
+  Linking Main.exe ...
+  \<linker warnings omitted\>
+  C:\\programming\\test\>copy Main.exe c:\\svc\\Test.exe
+      1 file(s) copied.
+  @
+  .
+  Execute the following from an elevated command prompt to register the
+  service:
+  .
+  @
+  C:\\svc\>sc create Test binPath= c:\\svc\\Test.exe
+  [SC] CreateService SUCCESS
+  @
+  .
+  The service can now be started and stopped from the services console.
+  .
+  Installation Notes:
+  .
+  Depending on which version of Windows and the Windows SDK you are using the
+  .cabal file will need to be modified before installing. A simple `cabal
+  install Win32-services` may not work. For example, If you are building on
+  Windows 8 64-bit with the Windows 8 SDK the 'extra-lib-dirs' field will need
+  to be changed to read as follows:
+  .
+  @
+  Extra-Lib-Dirs: \"C:\\\\Program Files (x86)\\\\Windows Kits\\\\8.0\\\\Lib\\\\win8\\\\um\\\\x86\"
+  @
+  .
+  Release Notes:
+  .
+  Changes in 0.2
+  .
+  * Writing services of the WIN32_OWN_PROCESS type is now easier. Handler
+  registration is performed automatically. By the time the service main
+  function is entered, the service will already be in the 'START_PENDING'
+  state. It is the user's responsibility to enter the 'RUNNING' state as soon
+  as possible.
+  .
+  * Once the service main function exits two things will occur. The service
+  will enter the 'STOPPED' state, and the handler function will be freed.
+  .
+  * The 'registerServiceCtrlHandlerEx' function is no longer
+  exported. Handlers are registered automatically by the
+  'startServiceCtrlDispatcher' function.
+  .
+  * The 'queryServiceStatus' function has been added.
+  .
+  Changes in 0.1
+  .
+  * First release
+extra-source-files: examples/*.hs
+
+source-repository head
+  type: git
+  location: git://github.com/mikesteele81/win32-services.git
+
+library
+  build-depends: base             >= 4.5 && < 4.6
+               , errors
+               , Win32
+  default-language: Haskell2010
+  ghc-options:     -Wall
+  hs-source-dirs: src
+  Exposed-Modules: System.Win32.SystemServices.Services
+  Extra-Libraries: Advapi32
+  other-modules: System.Win32.SystemServices.Services.SERVICE_STATUS
+               , System.Win32.SystemServices.Services.Raw
+               , System.Win32.SystemServices.Services.SERVICE_TABLE_ENTRY
+               , System.Win32.SystemServices.Services.Types
+               , System.Win32.SystemServices.Services.SERVICE_ACCEPT
+               , System.Win32.SystemServices.Services.SERVICE_CONTROL
+               , System.Win32.SystemServices.Services.SERVICE_STATE
+               , System.Win32.SystemServices.Services.SERVICE_TYPE
diff --git a/examples/official.hs b/examples/official.hs
--- a/examples/official.hs
+++ b/examples/official.hs
@@ -1,50 +1,48 @@
-module Main where
-
-import Control.Concurrent.MVar
-import System.Win32.SystemServices.Services
-import System.Win32.Types
-
-main :: IO ()
-main = startServiceCtrlDispatcher "Test" svcMain
-
-svcMain :: ServiceMainFunction
-svcMain name _ = do
-    gState <- newMVar (1, SERVICE_STATUS WIN32_OWN_PROCESS
-                          START_PENDING [] nO_ERROR 0 0 3000)
-    mStop <- newEmptyMVar
-    hStatus <- registerServiceCtrlHandlerEx name $ svcCtrlHandler mStop gState
-    
-    reportSvcStatus hStatus RUNNING nO_ERROR 0 gState
-    takeMVar mStop
-    reportSvcStatus hStatus STOPPED nO_ERROR 0 gState
-
-reportSvcStatus :: HANDLE -> SERVICE_STATE -> DWORD -> DWORD
-    -> MVar (DWORD, SERVICE_STATUS) -> IO ()
-reportSvcStatus hStatus state win32ExitCode waitHint mState = do
-    modifyMVar_ mState $ \(checkPoint, svcStatus) -> do
-        let state' = nextState (checkPoint, svcStatus
-             { win32ExitCode = win32ExitCode
-             , waitHint      = waitHint
-             , currentState  = state })
-        setServiceStatus hStatus (snd state')
-        return state'
-
-nextState :: (DWORD, SERVICE_STATUS) -> (DWORD, SERVICE_STATUS)
-nextState (checkPoint, svcStatus) = case (currentState svcStatus) of 
-    START_PENDING -> (checkPoint + 1, svcStatus
-        { controlsAccepted = [], checkPoint = checkPoint + 1 })
-    RUNNING -> (checkPoint, svcStatus
-        { controlsAccepted = [ACCEPT_STOP], checkPoint = 0 })
-    STOPPED -> (checkPoint, svcStatus
-        { controlsAccepted = [], checkPoint = 0 })
-    _ -> (checkPoint + 1, svcStatus
-        { controlsAccepted = [], checkPoint = checkPoint + 1 })
-
-svcCtrlHandler :: MVar () -> MVar (DWORD, SERVICE_STATUS)
-    -> HandlerFunction
-svcCtrlHandler mStop mState hStatus STOP = do
-    reportSvcStatus hStatus STOP_PENDING nO_ERROR 3000 mState
-    putMVar mStop ()
-    return True
-svcCtrlHandler _ _ _ INTERROGATE = return True
-svcCtrlHandler _ _ _ _  = return False
+module Main where
+
+import Control.Concurrent.MVar
+import System.Win32.SystemServices.Services
+import System.Win32.Types
+
+main :: IO ()
+main = do
+    gState <- newMVar (1, SERVICE_STATUS WIN32_OWN_PROCESS
+                          START_PENDING [] nO_ERROR 0 0 3000)
+    mStop <- newEmptyMVar
+    startServiceCtrlDispatcher "Test" 3000 (svcCtrlHandler mStop gState) $ svcMain mStop gState
+
+svcMain mStop gState _ _ h = do
+    reportSvcStatus h RUNNING nO_ERROR 0 gState
+    takeMVar mStop
+
+reportSvcStatus :: HANDLE -> SERVICE_STATE -> DWORD -> DWORD
+    -> MVar (DWORD, SERVICE_STATUS) -> IO ()
+reportSvcStatus hStatus state win32ExitCode waitHint mState = do
+    modifyMVar_ mState $ \(checkPoint, svcStatus) -> do
+        let state' = nextState (checkPoint, svcStatus
+             { win32ExitCode = win32ExitCode
+             , waitHint      = waitHint
+             , currentState  = state })
+        setServiceStatus hStatus (snd state')
+        return state'
+
+nextState :: (DWORD, SERVICE_STATUS) -> (DWORD, SERVICE_STATUS)
+nextState (checkPoint, svcStatus) = case (currentState svcStatus) of 
+    START_PENDING -> (checkPoint + 1, svcStatus
+        { controlsAccepted = [], checkPoint = checkPoint + 1 })
+    RUNNING -> (checkPoint, svcStatus
+        { controlsAccepted = [ACCEPT_STOP], checkPoint = 0 })
+    STOPPED -> (checkPoint, svcStatus
+        { controlsAccepted = [], checkPoint = 0 })
+    _ -> (checkPoint + 1, svcStatus
+        { controlsAccepted = [], checkPoint = checkPoint + 1 })
+
+svcCtrlHandler :: MVar () -> MVar (DWORD, SERVICE_STATUS)
+    -> HandlerFunction
+svcCtrlHandler mStop mState hStatus STOP = do
+    reportSvcStatus hStatus STOP_PENDING nO_ERROR 3000 mState
+    putMVar mStop ()
+    return True
+svcCtrlHandler _ _ _ INTERROGATE = return True
+svcCtrlHandler _ _ _ _  = return False
+
diff --git a/examples/simple.hs b/examples/simple.hs
--- a/examples/simple.hs
+++ b/examples/simple.hs
@@ -3,12 +3,11 @@
 import Control.Concurrent.MVar
 import System.Win32.SystemServices.Services
 
-main = startServiceCtrlDispatcher "Test" $ \name _ -> do
+main = do
     mStop <- newEmptyMVar
-    hStatus <- registerServiceCtrlHandlerEx name $ handler mStop
-    setServiceStatus hStatus running
-    takeMVar mStop
-    setServiceStatus hStatus stopped
+    startServiceCtrlDispatcher "Test" 3000 (handler mStop) $ \_ _ h -> do
+        setServiceStatus h running
+        takeMVar mStop
 
 handler mStop hStatus STOP = do
     setServiceStatus hStatus stopPending
@@ -17,8 +16,7 @@
 handler _ _ INTERROGATE = return True
 handler _ _ _           = return False
 
-stopped = SERVICE_STATUS WIN32_OWN_PROCESS STOPPED [] nO_ERROR 0 0 0
-stopPending = stopped { currentState = STOP_PENDING
+running = SERVICE_STATUS WIN32_OWN_PROCESS RUNNING [ACCEPT_STOP] nO_ERROR 0 0 0
+stopPending = running { currentState = STOP_PENDING
+                      , controlsAccepted = []
                       , waitHint = 3000 }
-running = stopped { currentState = RUNNING
-                  , controlsAccepted = [ACCEPT_STOP] }
diff --git a/src/System/Win32/SystemServices/Services.hs b/src/System/Win32/SystemServices/Services.hs
--- a/src/System/Win32/SystemServices/Services.hs
+++ b/src/System/Win32/SystemServices/Services.hs
@@ -1,151 +1,172 @@
-module System.Win32.SystemServices.Services
-    ( HandlerFunction
-    , ServiceMainFunction
-    , SERVICE_ACCEPT (..)
-    , SERVICE_CONTROL (..)
-    , SERVICE_STATE (..)
-    , SERVICE_STATUS (..)
-    , SERVICE_TYPE (..)
-    , nO_ERROR
-    , eRROR_SERVICE_SPECIFIC_ERROR
-    , registerServiceCtrlHandlerEx
-    , setServiceStatus
-    , startServiceCtrlDispatcher
-    ) where
-
-import Control.Exception
-import Control.Monad.Fix
-import Foreign
-import System.Win32.Types
-
-import System.Win32.SystemServices.Services.Raw
-import System.Win32.SystemServices.Services.SERVICE_ACCEPT
-import System.Win32.SystemServices.Services.SERVICE_CONTROL
-import qualified System.Win32.SystemServices.Services.SERVICE_CONTROL as SC
-import System.Win32.SystemServices.Services.SERVICE_STATE
-import System.Win32.SystemServices.Services.SERVICE_STATUS
-import System.Win32.SystemServices.Services.SERVICE_TABLE_ENTRY
-import System.Win32.SystemServices.Services.SERVICE_TYPE
-import System.Win32.SystemServices.Services.Types
-
--- | A handler function is registered with the service dispatcher thread
---   from a 'ServiceMainFunction'. The first argument is a 'HANDLE' returned
---   from calling 'registerServiceCtrlHandler'. The second argument represents
---   the command this service has been directed to perform.
-type HandlerFunction = HANDLE -> SERVICE_CONTROL -> IO Bool
-
--- | The service dispatcher thread will call each function of this type that
---   you provide. The first argument will be the name of the service. Any
---   additional command-line parameters will appear in the second argument.
---
---   Each of these functions should call 'registerServiceCtrlHandler' to
---   register a function to handle incoming commands. It should then set
---   the service's status to 'START_PENDING', and specify that no controls
---   will be accepted. At this point the function may perform any other
---   initialization steps before setting the service's status to
---   'RUNNING'. All of this should take no more than 100ms.
-type ServiceMainFunction = String -> [String] -> IO ()
-
--- | Register an handler function to be called whenever the operating system
--- receives service control messages.
---
--- NOTE: This function creates a FunPtr which is never freed.
-registerServiceCtrlHandlerEx :: String
-    -- ^ The name of the service. According to MSDN documentation this
-    -- argument is unused in WIN32_OWN_PROCESS type services, which is the
-    -- only type supported by this binding. Even so, it is recommended
-    -- that the name of the service be used.
-    --
-    -- MSDN description: The name of the service run by the calling thread.
-    -- This is the service name that the service control program specified in
-    -- the CreateService function when creating the service.
-    -> HandlerFunction
-    -- ^ A Handler function to be called in response to service control
-    -- messages. Behind the scenes this is translated into a "HandlerEx" type
-    -- handler.
-    -> IO HANDLE
-    -- ^ The returned handle may be used in calls to SetServiceStatus. For
-    -- convenience Handler functions also receive a handle for the service.
-registerServiceCtrlHandlerEx str handler =
-    withTString str $ \lptstr ->
-    mfix $ \hStatus -> do
-    -- FIXME: FunPtrs need to be manually freed
-    fpHandler <- handlerToFunPtr . toHandlerEx hStatus $ handler
-    failIfNull (unwords ["RegisterServiceCtrlHandlerEx", str])
-        $ c_RegisterServiceCtrlHandlerEx lptstr fpHandler nullPtr
-
--- |Updates the service control manager's status information for the calling
--- service.
-setServiceStatus :: HANDLE
-    -- ^ MSDN documentation: A handle to the status information structure for
-    -- the current service. This handle is returned by the
-    -- RegisterServiceCtrlHandlerEx function.
-    -> SERVICE_STATUS
-    -- ^ MSDN documentation: A pointer to the SERVICE_STATUS structure the
-    -- contains the latest status information for the calling service.
-    -> IO ()
-    -- ^ This function will raise an exception if the Win32 call returned an
-    -- error condition.
-setServiceStatus h status =
-    with status $ \pStatus -> do
-    failIfFalse_ (unwords ["SetServiceStatus", show h, show status])
-        $ c_SetServiceStatus h pStatus
-
--- |Register a callback function to initialize the service, which will be
--- called by the operating system immediately. startServiceCtrlDispatcher
--- will block until the provided callback function returns.
---
--- MSDN documentation: Connects the main thread of a service process to the
--- service control manager, which causes the thread to be the service control
--- dispatcher thread for the calling process.
-startServiceCtrlDispatcher :: String
-    -- ^ The name of the service. According to MSDN documentation this
-    -- argument is unused in WIN32_OWN_PROCESS type services, which is the
-    -- only type supported by this binding. Even so, it is recommended
-    -- that the name of the service be used.
-    --
-    -- MSDN description: The name of the service run by the calling thread.
-    -- This is the service name that the service control program specified in
-    -- the CreateService function when creating the service.
-    -> ServiceMainFunction
-    -- ^ This is a callback function that will be called by the operating
-    -- system whenever the service is started. It should perform service
-    -- initialization including the registration of a handler function.
-    -- MSDN documentation gives conflicting advice as to whether this function
-    -- should return before the service has entered the stopped state.
-    -- In the official example the service main function blocks until the
-    -- service is ready to stop.
-    -> IO ()
-    -- ^ An exception will be raised if the underlying Win32 call returns an
-    -- error condition.
-startServiceCtrlDispatcher name main =
-    withTString name $ \lptstr ->
-    bracket (smfToFunPtr . toSMF $ main) freeHaskellFunPtr $ \fpMain ->
-    withArray [SERVICE_TABLE_ENTRY lptstr fpMain, nullSTE] $ \pSTE ->
-    failIfFalse_ (unwords ["StartServiceCtrlDispatcher", name])
-    $ c_StartServiceCtrlDispatcher pSTE
-
-toSMF :: ServiceMainFunction -> SERVICE_MAIN_FUNCTION
-toSMF f = \len -> \pLPTSTR -> do
-    lptstrx <- peekArray (fromIntegral len) pLPTSTR
-    args <- mapM peekTString lptstrx
-    -- MSDN guarantees args will have at least 1 member.
-    f (head args) (tail args)
-
--- This was originally written with older style handle functions in mind.
--- I'm now using HandlerEx style functions, and need to add support for
--- the extra parameters here.
-toHandlerEx :: HANDLE -> HandlerFunction -> HANDLER_FUNCTION_EX
-toHandlerEx h f = \dwControl _ _ _ ->
-    case SC.fromDWORD dwControl of
-      Right control -> do
-          handled <- f h control
-          case control of
-            INTERROGATE -> return nO_ERROR
-            -- If we ever support extended control codes this will have to
-            -- change. see "Dev Center - Desktop > Docs > Desktop app
-            -- development documentation > System Services > Services >
-            -- Service Reference > Service Functions > HandlerEx".
-            _ -> return $ if handled then nO_ERROR
-                                     else eRROR_CALL_NOT_IMPLEMENTED
-      Left _ -> return eRROR_CALL_NOT_IMPLEMENTED
+module System.Win32.SystemServices.Services
+    ( HandlerFunction
+    , ServiceMainFunction
+    , SERVICE_ACCEPT (..)
+    , SERVICE_CONTROL (..)
+    , SERVICE_STATE (..)
+    , SERVICE_STATUS (..)
+    , SERVICE_TYPE (..)
+    , nO_ERROR
+    , eRROR_SERVICE_SPECIFIC_ERROR
+    , queryServiceStatus
+    , setServiceStatus
+    , startServiceCtrlDispatcher
+    ) where
+
+import Control.Exception
+import Control.Monad.Fix
+import Foreign
+import System.Win32.Types
+
+import System.Win32.SystemServices.Services.Raw
+import System.Win32.SystemServices.Services.SERVICE_ACCEPT
+import System.Win32.SystemServices.Services.SERVICE_CONTROL
+import qualified System.Win32.SystemServices.Services.SERVICE_CONTROL as SC
+import System.Win32.SystemServices.Services.SERVICE_STATE
+import System.Win32.SystemServices.Services.SERVICE_STATUS
+import System.Win32.SystemServices.Services.SERVICE_TABLE_ENTRY
+import System.Win32.SystemServices.Services.SERVICE_TYPE
+import System.Win32.SystemServices.Services.Types
+
+-- | A handler function is registered with the service dispatcher thread
+--   from a 'ServiceMainFunction'. The first argument is a 'HANDLE' returned
+--   from calling 'registerServiceCtrlHandler'. The second argument represents
+--   the command this service has been directed to perform.
+type HandlerFunction = HANDLE -> SERVICE_CONTROL -> IO Bool
+
+-- | The service dispatcher thread will call each function of this type that
+--   you provide. The first argument will be the name of the service. Any
+--   additional command-line parameters will appear in the second argument.
+--
+--   Each of these functions should call 'registerServiceCtrlHandler' to
+--   register a function to handle incoming commands. It should then set
+--   the service's status to 'START_PENDING', and specify that no controls
+--   will be accepted. At this point the function may perform any other
+--   initialization steps before setting the service's status to
+--   'RUNNING'. All of this should take no more than 100ms.
+type ServiceMainFunction = String -> [String] -> HANDLE -> IO ()
+
+-- |Retrieves the current status of the specified service.
+queryServiceStatus :: HANDLE
+    -- ^ MSDN documentation: A handle to the service. This handle is returned
+    -- by the OpenService or the CreateService function, and it must have the
+    -- SERVICE_QUERY_STATUS access right. For more information, see Service
+    -- Security and Access Rights.
+    -> IO SERVICE_STATUS
+    -- ^ This function will raise an exception if the Win32 call returned an
+    -- error condition.
+queryServiceStatus h = alloca $ \pStatus -> do
+    failIfFalse_ (unwords ["QueryServiceStatus"])
+        $ c_QueryServiceStatus h pStatus
+    peek pStatus
+
+-- | Register an handler function to be called whenever the operating system
+-- receives service control messages.
+registerServiceCtrlHandlerEx :: String
+    -- ^ The name of the service. According to MSDN documentation this
+    -- argument is unused in WIN32_OWN_PROCESS type services, which is the
+    -- only type supported by this binding. Even so, it is recommended
+    -- that the name of the service be used.
+    --
+    -- MSDN description: The name of the service run by the calling thread.
+    -- This is the service name that the service control program specified in
+    -- the CreateService function when creating the service.
+    -> HandlerFunction
+    -- ^ A Handler function to be called in response to service control
+    -- messages. Behind the scenes this is translated into a "HandlerEx" type
+    -- handler.
+    -> IO (HANDLE, LPHANDLER_FUNCTION_EX)
+    -- ^ The returned handle may be used in calls to SetServiceStatus. For
+    -- convenience Handler functions also receive a handle for the service.
+registerServiceCtrlHandlerEx str handler =
+    withTString str $ \lptstr ->
+    -- use 'ret' instead of (h', _) to avoid divergence.
+    mfix $ \ret -> do
+    fpHandler <- handlerToFunPtr $ toHandlerEx (fst ret) handler
+    h <- failIfNull (unwords ["RegisterServiceCtrlHandlerEx", str])
+        $ c_RegisterServiceCtrlHandlerEx lptstr fpHandler nullPtr
+    return (h, fpHandler)
+
+-- |Updates the service control manager's status information for the calling
+-- service.
+setServiceStatus :: HANDLE
+    -- ^ MSDN documentation: A handle to the status information structure for
+    -- the current service. This handle is returned by the
+    -- RegisterServiceCtrlHandlerEx function.
+    -> SERVICE_STATUS
+    -- ^ MSDN documentation: A pointer to the SERVICE_STATUS structure the
+    -- contains the latest status information for the calling service.
+    -> IO ()
+    -- ^ This function will raise an exception if the Win32 call returned an
+    -- error condition.
+setServiceStatus h status =
+    with status $ \pStatus -> do
+    failIfFalse_ (unwords ["SetServiceStatus", show h, show status])
+        $ c_SetServiceStatus h pStatus
+
+-- |Register a callback function to initialize the service, which will be
+-- called by the operating system immediately. startServiceCtrlDispatcher
+-- will block until the provided callback function returns.
+--
+-- MSDN documentation: Connects the main thread of a service process to the
+-- service control manager, which causes the thread to be the service control
+-- dispatcher thread for the calling process.
+startServiceCtrlDispatcher :: String
+    -- ^ The name of the service. According to MSDN documentation this
+    -- argument is unused in WIN32_OWN_PROCESS type services, which is the
+    -- only type supported by this binding. Even so, it is recommended
+    -- that the name of the service be used.
+    --
+    -- MSDN description: The name of the service run by the calling thread.
+    -- This is the service name that the service control program specified in
+    -- the CreateService function when creating the service.
+    -> DWORD
+    -> HandlerFunction
+    -> ServiceMainFunction
+    -- ^ This is a callback function that will be called by the operating
+    -- system whenever the service is started. It should perform service
+    -- initialization including the registration of a handler function.
+    -- MSDN documentation gives conflicting advice as to whether this function
+    -- should return before the service has entered the stopped state.
+    -- In the official example the service main function blocks until the
+    -- service is ready to stop.
+    -> IO ()
+    -- ^ An exception will be raised if the underlying Win32 call returns an
+    -- error condition.
+startServiceCtrlDispatcher name wh handler main =
+    withTString name $ \lptstr ->
+    bracket (toSMF main handler wh >>= smfToFunPtr) freeHaskellFunPtr $ \fpMain ->
+    withArray [SERVICE_TABLE_ENTRY lptstr fpMain, nullSTE] $ \pSTE ->
+    failIfFalse_ (unwords ["StartServiceCtrlDispatcher", name]) $ do
+    c_StartServiceCtrlDispatcher pSTE
+
+toSMF :: ServiceMainFunction -> HandlerFunction -> DWORD -> IO SERVICE_MAIN_FUNCTION
+toSMF f handler wh = return $ \len pLPTSTR -> do
+    lptstrx <- peekArray (fromIntegral len) pLPTSTR
+    args <- mapM peekTString lptstrx
+    -- MSDN guarantees args will have at least 1 member.
+    let name = head args
+    (h, fpHandler) <- registerServiceCtrlHandlerEx name handler
+    setServiceStatus h $ SERVICE_STATUS WIN32_OWN_PROCESS START_PENDING [] nO_ERROR 0 0 wh
+    f name (tail args) h
+    status <- queryServiceStatus h
+    setServiceStatus h $ status {currentState = STOPPED, controlsAccepted = []}
+    freeHaskellFunPtr fpHandler
+
+-- This was originally written with older style handle functions in mind.
+-- I'm now using HandlerEx style functions, and need to add support for
+-- the extra parameters here.
+toHandlerEx :: HANDLE -> HandlerFunction -> HANDLER_FUNCTION_EX
+toHandlerEx h f = \dwControl _ _ _ ->
+    case SC.fromDWORD dwControl of
+      Right control -> do
+          handled <- f h control
+          case control of
+            INTERROGATE -> return nO_ERROR
+            -- If we ever support extended control codes this will have to
+            -- change. see "Dev Center - Desktop > Docs > Desktop app
+            -- development documentation > System Services > Services >
+            -- Service Reference > Service Functions > HandlerEx".
+            _ -> return $ if handled then nO_ERROR
+                                     else eRROR_CALL_NOT_IMPLEMENTED
+      Left _ -> return eRROR_CALL_NOT_IMPLEMENTED
diff --git a/src/System/Win32/SystemServices/Services/Raw.hs b/src/System/Win32/SystemServices/Services/Raw.hs
--- a/src/System/Win32/SystemServices/Services/Raw.hs
+++ b/src/System/Win32/SystemServices/Services/Raw.hs
@@ -1,26 +1,33 @@
-{-# LANGUAGE ForeignFunctionInterface #-}
-
-module System.Win32.SystemServices.Services.Raw where
-
-import Foreign.Ptr (Ptr)
-import System.Win32.Types
-
-import System.Win32.SystemServices.Services.SERVICE_STATUS
-import System.Win32.SystemServices.Services.SERVICE_TABLE_ENTRY
-import System.Win32.SystemServices.Services.Types
-
-foreign import stdcall "wrapper"
-    smfToFunPtr :: SERVICE_MAIN_FUNCTION -> IO LPSERVICE_MAIN_FUNCTION
-
-foreign import stdcall "wrapper"
-    handlerToFunPtr :: HANDLER_FUNCTION_EX -> IO LPHANDLER_FUNCTION_EX
-
--- I've not been able to get RegisterServiceCtrlHandler to work on Windows 7 64-bit.
-foreign import stdcall "windows.h RegisterServiceCtrlHandlerExW"
-    c_RegisterServiceCtrlHandlerEx :: LPTSTR -> LPHANDLER_FUNCTION_EX  -> Ptr () -> IO HANDLE
-
-foreign import stdcall "windows.h SetServiceStatus"
-    c_SetServiceStatus :: HANDLE -> Ptr SERVICE_STATUS -> IO BOOL
-
-foreign import stdcall "windows.h StartServiceCtrlDispatcherW"
-    c_StartServiceCtrlDispatcher :: Ptr SERVICE_TABLE_ENTRY -> IO BOOL
+{-# LANGUAGE ForeignFunctionInterface #-}
+
+module System.Win32.SystemServices.Services.Raw where
+
+import Foreign.Ptr (Ptr)
+import System.Win32.Types
+
+import System.Win32.SystemServices.Services.SERVICE_STATUS
+import System.Win32.SystemServices.Services.SERVICE_TABLE_ENTRY
+import System.Win32.SystemServices.Services.Types
+
+foreign import stdcall "wrapper"
+    smfToFunPtr :: SERVICE_MAIN_FUNCTION -> IO LPSERVICE_MAIN_FUNCTION
+
+foreign import stdcall "wrapper"
+    handlerToFunPtr :: HANDLER_FUNCTION_EX -> IO LPHANDLER_FUNCTION_EX
+
+-- BOOL WINAPI QueryServiceStatus(
+--   _In_   SC_HANDLE hService,
+--   _Out_  LPSERVICE_STATUS lpServiceStatus
+-- );
+foreign import stdcall "windows.h QueryServiceStatus"
+    c_QueryServiceStatus :: HANDLE -> Ptr SERVICE_STATUS -> IO BOOL
+
+-- I've not been able to get RegisterServiceCtrlHandler to work on Windows 7 64-bit.
+foreign import stdcall "windows.h RegisterServiceCtrlHandlerExW"
+    c_RegisterServiceCtrlHandlerEx :: LPTSTR -> LPHANDLER_FUNCTION_EX  -> Ptr () -> IO HANDLE
+
+foreign import stdcall "windows.h SetServiceStatus"
+    c_SetServiceStatus :: HANDLE -> Ptr SERVICE_STATUS -> IO BOOL
+
+foreign import stdcall "windows.h StartServiceCtrlDispatcherW"
+    c_StartServiceCtrlDispatcher :: Ptr SERVICE_TABLE_ENTRY -> IO BOOL
diff --git a/src/System/Win32/SystemServices/Services/SERVICE_ACCEPT.hs b/src/System/Win32/SystemServices/Services/SERVICE_ACCEPT.hs
--- a/src/System/Win32/SystemServices/Services/SERVICE_ACCEPT.hs
+++ b/src/System/Win32/SystemServices/Services/SERVICE_ACCEPT.hs
@@ -1,92 +1,92 @@
-module System.Win32.SystemServices.Services.SERVICE_ACCEPT
-    ( SERVICE_ACCEPT (..)
-    , pokeServiceAccept
-    , peekServiceAccept
-    ) where
-
-import Control.Applicative
-import Data.Bits
-import Data.Maybe
-import Foreign
-import System.Win32.Types (DWORD)
-import Text.Printf
-
-import Control.Error
-
--- | The control codes the service accepts and processes in its handler
---   function (See 'HandlerFunction'). By default, all services accept the
---   'INTERROGATE' value. To accept the 'DEVICEEVENT' value, the service must
---   register to receive device events by using the
---   'registerDeviceNotification' function.
-data SERVICE_ACCEPT
-    -- | The service is a network component that can accept changes in its
-    --   binding without being stopped and restarted. This control code allows
-    --   the service to receive 'NETBINDADD', 'NETBINDREMOVE', 'NETBINDENABLE'
-    --   , and 'NETBINDDISABLE' notifications.
-    = ACCEPT_NETBINDCHANGE
-    -- | The service can reread its startup parameters without being stopped
-    --   and restarted. This control code allows the service to receive
-    --   'PARAMCHANGE' notifications.
-    | ACCEPT_PARAMCHANGE
-    -- | The service can be paused and continued. This control code allows the
-    --   service to receive 'PAUSE' and 'CONTINUE' notifications.
-    | ACCEPT_PAUSE_CONTINUE
-    -- | MSDN documentation says that this function is not supported on
-    --   Windows Server 2003 or Windows XP/2000. The support status on other
-    --   versions is unknown to me.
-    --
-    --   The service can perform preshutdown tasks. This control code enables
-    --   the service to receive 'PRESHUTDOWN' notifications.
-    --   Note that only the system can send it.
-    | ACCEPT_PRESHUTDOWN
-    -- | The service is notified when system shutdown occurs. This control
-    --   code allows the service to receive 'SHUTDOWN' notifications. Note
-    --   that only the system can send it.
-    | ACCEPT_SHUTDOWN
-    -- | The service can be stopped. This control code allows the service to
-    --   receive 'STOP' notifications.
-    | ACCEPT_STOP
-    deriving (Show)
-
-peekServiceAccept :: Ptr DWORD -> IO [SERVICE_ACCEPT]
-peekServiceAccept ptr = unflag <$> peek ptr
-
-pokeServiceAccept :: Ptr DWORD -> [SERVICE_ACCEPT] -> IO ()
-pokeServiceAccept ptr sas = poke ptr . flag $ sas
-
-toDWORD :: SERVICE_ACCEPT -> DWORD
-toDWORD ACCEPT_NETBINDCHANGE  = 0x00000010
-toDWORD ACCEPT_PARAMCHANGE    = 0x00000008
-toDWORD ACCEPT_PAUSE_CONTINUE = 0x00000002
-toDWORD ACCEPT_PRESHUTDOWN    = 0x00000100
-toDWORD ACCEPT_SHUTDOWN       = 0x00000004
-toDWORD ACCEPT_STOP           = 0x00000001
-
-fromDWORD :: DWORD -> Either String SERVICE_ACCEPT
-fromDWORD 0x00000010 = Right ACCEPT_NETBINDCHANGE
-fromDWORD 0x00000008 = Right ACCEPT_PARAMCHANGE
-fromDWORD 0x00000002 = Right ACCEPT_PAUSE_CONTINUE
-fromDWORD 0x00000100 = Right ACCEPT_PRESHUTDOWN
-fromDWORD 0x00000004 = Right ACCEPT_SHUTDOWN
-fromDWORD 0x00000001 = Right ACCEPT_STOP
-fromDWORD 0x00000020 = unsupported "SERVICE_ACCEPT_HARDWAREPROFILECHANGE"
-fromDWORD 0x00000040 = unsupported "SERVICE_ACCEPT_POWEREVENT"
-fromDWORD 0x00000080 = unsupported "SERVICE_ACCEPT_SESSIONCHANGE"
-fromDWORD 0x00000200 = unsupported "SERVICE_ACCEPT_TIMECHANGE"
-fromDWORD 0x00000400 = unsupported "SERVICE_ACCEPT_TRIGGEREVENT"
-fromDWORD 0x00000800 = unsupported "SERVICE_ACCEPT_USERMODEREBOOT"
-fromDWORD x = Left $ "The " ++ printf "%x" x ++ " control code is undocumented."
-
-unsupported :: String -> Either String a
-unsupported name = Left $ "The " ++ name ++ " control code is unsupported by this binding."
-
--- | This function takes a 'DWORD' and assumes it is a flagfield. Each bit
---   is masked off and converted into a value. Any failures are silently
---   discarded.
-unflag :: DWORD -> [SERVICE_ACCEPT]
-unflag f = mapMaybe (hush . fromDWORD . (.&. f)) masks
-  where
-    masks = take 32 $ iterate (`shiftL` 1) 1
-
-flag :: [SERVICE_ACCEPT] -> DWORD
+module System.Win32.SystemServices.Services.SERVICE_ACCEPT
+    ( SERVICE_ACCEPT (..)
+    , pokeServiceAccept
+    , peekServiceAccept
+    ) where
+
+import Control.Applicative
+import Data.Bits
+import Data.Maybe
+import Foreign
+import System.Win32.Types (DWORD)
+import Text.Printf
+
+import Control.Error
+
+-- | The control codes the service accepts and processes in its handler
+--   function (See 'HandlerFunction'). By default, all services accept the
+--   'INTERROGATE' value. To accept the 'DEVICEEVENT' value, the service must
+--   register to receive device events by using the
+--   'registerDeviceNotification' function.
+data SERVICE_ACCEPT
+    -- | The service is a network component that can accept changes in its
+    --   binding without being stopped and restarted. This control code allows
+    --   the service to receive 'NETBINDADD', 'NETBINDREMOVE', 'NETBINDENABLE'
+    --   , and 'NETBINDDISABLE' notifications.
+    = ACCEPT_NETBINDCHANGE
+    -- | The service can reread its startup parameters without being stopped
+    --   and restarted. This control code allows the service to receive
+    --   'PARAMCHANGE' notifications.
+    | ACCEPT_PARAMCHANGE
+    -- | The service can be paused and continued. This control code allows the
+    --   service to receive 'PAUSE' and 'CONTINUE' notifications.
+    | ACCEPT_PAUSE_CONTINUE
+    -- | MSDN documentation says that this function is not supported on
+    --   Windows Server 2003 or Windows XP/2000. The support status on other
+    --   versions is unknown to me.
+    --
+    --   The service can perform preshutdown tasks. This control code enables
+    --   the service to receive 'PRESHUTDOWN' notifications.
+    --   Note that only the system can send it.
+    | ACCEPT_PRESHUTDOWN
+    -- | The service is notified when system shutdown occurs. This control
+    --   code allows the service to receive 'SHUTDOWN' notifications. Note
+    --   that only the system can send it.
+    | ACCEPT_SHUTDOWN
+    -- | The service can be stopped. This control code allows the service to
+    --   receive 'STOP' notifications.
+    | ACCEPT_STOP
+    deriving (Show)
+
+peekServiceAccept :: Ptr DWORD -> IO [SERVICE_ACCEPT]
+peekServiceAccept ptr = unflag <$> peek ptr
+
+pokeServiceAccept :: Ptr DWORD -> [SERVICE_ACCEPT] -> IO ()
+pokeServiceAccept ptr sas = poke ptr . flag $ sas
+
+toDWORD :: SERVICE_ACCEPT -> DWORD
+toDWORD ACCEPT_NETBINDCHANGE  = 0x00000010
+toDWORD ACCEPT_PARAMCHANGE    = 0x00000008
+toDWORD ACCEPT_PAUSE_CONTINUE = 0x00000002
+toDWORD ACCEPT_PRESHUTDOWN    = 0x00000100
+toDWORD ACCEPT_SHUTDOWN       = 0x00000004
+toDWORD ACCEPT_STOP           = 0x00000001
+
+fromDWORD :: DWORD -> Either String SERVICE_ACCEPT
+fromDWORD 0x00000010 = Right ACCEPT_NETBINDCHANGE
+fromDWORD 0x00000008 = Right ACCEPT_PARAMCHANGE
+fromDWORD 0x00000002 = Right ACCEPT_PAUSE_CONTINUE
+fromDWORD 0x00000100 = Right ACCEPT_PRESHUTDOWN
+fromDWORD 0x00000004 = Right ACCEPT_SHUTDOWN
+fromDWORD 0x00000001 = Right ACCEPT_STOP
+fromDWORD 0x00000020 = unsupported "SERVICE_ACCEPT_HARDWAREPROFILECHANGE"
+fromDWORD 0x00000040 = unsupported "SERVICE_ACCEPT_POWEREVENT"
+fromDWORD 0x00000080 = unsupported "SERVICE_ACCEPT_SESSIONCHANGE"
+fromDWORD 0x00000200 = unsupported "SERVICE_ACCEPT_TIMECHANGE"
+fromDWORD 0x00000400 = unsupported "SERVICE_ACCEPT_TRIGGEREVENT"
+fromDWORD 0x00000800 = unsupported "SERVICE_ACCEPT_USERMODEREBOOT"
+fromDWORD x = Left $ "The " ++ printf "%x" x ++ " control code is undocumented."
+
+unsupported :: String -> Either String a
+unsupported name = Left $ "The " ++ name ++ " control code is unsupported by this binding."
+
+-- | This function takes a 'DWORD' and assumes it is a flagfield. Each bit
+--   is masked off and converted into a value. Any failures are silently
+--   discarded.
+unflag :: DWORD -> [SERVICE_ACCEPT]
+unflag f = mapMaybe (hush . fromDWORD . (.&. f)) masks
+  where
+    masks = take 32 $ iterate (`shiftL` 1) 1
+
+flag :: [SERVICE_ACCEPT] -> DWORD
 flag fs = foldl (\flag' f -> flag' .|. toDWORD f) 0 fs
diff --git a/src/System/Win32/SystemServices/Services/SERVICE_CONTROL.hs b/src/System/Win32/SystemServices/Services/SERVICE_CONTROL.hs
--- a/src/System/Win32/SystemServices/Services/SERVICE_CONTROL.hs
+++ b/src/System/Win32/SystemServices/Services/SERVICE_CONTROL.hs
@@ -1,68 +1,68 @@
-module System.Win32.SystemServices.Services.SERVICE_CONTROL
-    ( SERVICE_CONTROL (..)
-    , peekServiceControl
-    , pokeServiceControl
-    , fromDWORD
-    ) where
-
-import Foreign
-import System.Win32.Types (DWORD)
-import Text.Printf
-
-import Control.Error
-
--- | A SERVICE_CONTROL is used in Handler functions. All control codes are
---   defined here, but some can only be used with a 'HandlerEx' callback.
---   Use 'convertSuccess' to translate from a 'SERVICE_CONTROL' to a 'DWORD'.
---   Use 'convertAttempt' to translate from a 'DWORD' to a 'SERVICE_CONTROL'.
-data SERVICE_CONTROL = CONTINUE | INTERROGATE | NETBINDADD | NETBINDDISABLE
-    | NETBINDENABLE | NETBINDREMOVE | PARAMCHANGE | PAUSE
-    | PRESHUTDOWN | SHUTDOWN | STOP
-    deriving (Show)
-
-peekServiceControl :: Ptr DWORD -> IO SERVICE_CONTROL
-peekServiceControl ptr = runScript $ do
-    dword <- scriptIO $ peek ptr
-    hoistEither $ fromDWORD dword
-
-pokeServiceControl :: Ptr DWORD -> SERVICE_CONTROL -> IO ()
-pokeServiceControl ptr sc = poke ptr . toDWORD $ sc
-
-toDWORD :: SERVICE_CONTROL -> DWORD
-toDWORD CONTINUE       = 0x00000003
-toDWORD INTERROGATE    = 0x00000004
-toDWORD NETBINDADD     = 0x00000007
-toDWORD NETBINDDISABLE = 0x0000000A
-toDWORD NETBINDENABLE  = 0x00000009
-toDWORD NETBINDREMOVE  = 0x00000008
-toDWORD PARAMCHANGE    = 0x00000006
-toDWORD PAUSE          = 0x00000002
-toDWORD PRESHUTDOWN    = 0x0000000F
-toDWORD SHUTDOWN       = 0x00000005
-toDWORD STOP           = 0x00000001
-
-fromDWORD :: DWORD -> Either String SERVICE_CONTROL
-fromDWORD 0x00000003 = Right CONTINUE
-fromDWORD 0x00000004 = Right INTERROGATE
-fromDWORD 0x00000007 = Right NETBINDADD
-fromDWORD 0x0000000A = Right NETBINDDISABLE
-fromDWORD 0x00000009 = Right NETBINDENABLE
-fromDWORD 0x00000008 = Right NETBINDREMOVE
-fromDWORD 0x00000006 = Right PARAMCHANGE
-fromDWORD 0x00000002 = Right PAUSE
-fromDWORD 0x0000000F = Right PRESHUTDOWN
-fromDWORD 0x00000005 = Right SHUTDOWN
-fromDWORD 0x00000001 = Right STOP
-fromDWORD 0x0000000B = unsupported "SERVICE_CONTROL_DEVICEEVENT"
-fromDWORD 0x0000000C = unsupported "SERVICE_CONTROL_HARDWAREPROFILECHANGE"
-fromDWORD 0x0000000D = unsupported "SERVICE_CONTROL_POWEREVENT"
-fromDWORD 0x0000000E = unsupported "SERVICE_CONTROL_SESSIONCHANGE"
-fromDWORD 0x00000010 = unsupported "SERVICE_CONTROL_TIMECHANGE"
-fromDWORD 0x00000020 = unsupported "SERVICE_CONTROL_TRIGGEREVENT"
-fromDWORD 0x00000040 = unsupported "SERVICE_CONTROL_USERMODEREBOOT"
-fromDWORD x
-    | x >= 128 && x <= 255 = Left "user defined control codes are unsupported by this binding."
-    | otherwise = Left $ "The " ++ printf "%x" x ++ " control code is undocumented."
-
-unsupported :: String -> Either String a
-unsupported name = Left $ "The " ++ name ++ " control code is unsupported by this binding."
+module System.Win32.SystemServices.Services.SERVICE_CONTROL
+    ( SERVICE_CONTROL (..)
+    , peekServiceControl
+    , pokeServiceControl
+    , fromDWORD
+    ) where
+
+import Foreign
+import System.Win32.Types (DWORD)
+import Text.Printf
+
+import Control.Error
+
+-- | A SERVICE_CONTROL is used in Handler functions. All control codes are
+--   defined here, but some can only be used with a 'HandlerEx' callback.
+--   Use 'convertSuccess' to translate from a 'SERVICE_CONTROL' to a 'DWORD'.
+--   Use 'convertAttempt' to translate from a 'DWORD' to a 'SERVICE_CONTROL'.
+data SERVICE_CONTROL = CONTINUE | INTERROGATE | NETBINDADD | NETBINDDISABLE
+    | NETBINDENABLE | NETBINDREMOVE | PARAMCHANGE | PAUSE
+    | PRESHUTDOWN | SHUTDOWN | STOP
+    deriving (Show)
+
+peekServiceControl :: Ptr DWORD -> IO SERVICE_CONTROL
+peekServiceControl ptr = runScript $ do
+    dword <- scriptIO $ peek ptr
+    hoistEither $ fromDWORD dword
+
+pokeServiceControl :: Ptr DWORD -> SERVICE_CONTROL -> IO ()
+pokeServiceControl ptr sc = poke ptr . toDWORD $ sc
+
+toDWORD :: SERVICE_CONTROL -> DWORD
+toDWORD CONTINUE       = 0x00000003
+toDWORD INTERROGATE    = 0x00000004
+toDWORD NETBINDADD     = 0x00000007
+toDWORD NETBINDDISABLE = 0x0000000A
+toDWORD NETBINDENABLE  = 0x00000009
+toDWORD NETBINDREMOVE  = 0x00000008
+toDWORD PARAMCHANGE    = 0x00000006
+toDWORD PAUSE          = 0x00000002
+toDWORD PRESHUTDOWN    = 0x0000000F
+toDWORD SHUTDOWN       = 0x00000005
+toDWORD STOP           = 0x00000001
+
+fromDWORD :: DWORD -> Either String SERVICE_CONTROL
+fromDWORD 0x00000003 = Right CONTINUE
+fromDWORD 0x00000004 = Right INTERROGATE
+fromDWORD 0x00000007 = Right NETBINDADD
+fromDWORD 0x0000000A = Right NETBINDDISABLE
+fromDWORD 0x00000009 = Right NETBINDENABLE
+fromDWORD 0x00000008 = Right NETBINDREMOVE
+fromDWORD 0x00000006 = Right PARAMCHANGE
+fromDWORD 0x00000002 = Right PAUSE
+fromDWORD 0x0000000F = Right PRESHUTDOWN
+fromDWORD 0x00000005 = Right SHUTDOWN
+fromDWORD 0x00000001 = Right STOP
+fromDWORD 0x0000000B = unsupported "SERVICE_CONTROL_DEVICEEVENT"
+fromDWORD 0x0000000C = unsupported "SERVICE_CONTROL_HARDWAREPROFILECHANGE"
+fromDWORD 0x0000000D = unsupported "SERVICE_CONTROL_POWEREVENT"
+fromDWORD 0x0000000E = unsupported "SERVICE_CONTROL_SESSIONCHANGE"
+fromDWORD 0x00000010 = unsupported "SERVICE_CONTROL_TIMECHANGE"
+fromDWORD 0x00000020 = unsupported "SERVICE_CONTROL_TRIGGEREVENT"
+fromDWORD 0x00000040 = unsupported "SERVICE_CONTROL_USERMODEREBOOT"
+fromDWORD x
+    | x >= 128 && x <= 255 = Left "user defined control codes are unsupported by this binding."
+    | otherwise = Left $ "The " ++ printf "%x" x ++ " control code is undocumented."
+
+unsupported :: String -> Either String a
+unsupported name = Left $ "The " ++ name ++ " control code is unsupported by this binding."
diff --git a/src/System/Win32/SystemServices/Services/SERVICE_STATE.hs b/src/System/Win32/SystemServices/Services/SERVICE_STATE.hs
--- a/src/System/Win32/SystemServices/Services/SERVICE_STATE.hs
+++ b/src/System/Win32/SystemServices/Services/SERVICE_STATE.hs
@@ -1,56 +1,56 @@
-module System.Win32.SystemServices.Services.SERVICE_STATE
-    ( SERVICE_STATE (..)
-    , nO_ERROR
-    , eRROR_CALL_NOT_IMPLEMENTED
-    , eRROR_SERVICE_SPECIFIC_ERROR
-    , peekServiceState
-    , pokeServiceState
-    ) where
-
-import Foreign
-import System.Win32.Types
-import Text.Printf
-
-import Control.Error
-
-nO_ERROR :: ErrCode
-nO_ERROR = 0
-
-eRROR_CALL_NOT_IMPLEMENTED :: ErrCode
-eRROR_CALL_NOT_IMPLEMENTED = 0x78
-
-eRROR_SERVICE_SPECIFIC_ERROR :: ErrCode
-eRROR_SERVICE_SPECIFIC_ERROR = 0x429
-
--- | The current state of a service.
-data SERVICE_STATE = CONTINUE_PENDING | PAUSE_PENDING | PAUSED | RUNNING
-    | START_PENDING | STOP_PENDING | STOPPED
-    deriving (Eq, Show)
-
-fromDWORD :: DWORD -> Either String SERVICE_STATE
-fromDWORD 5 = Right CONTINUE_PENDING
-fromDWORD 6 = Right PAUSE_PENDING
-fromDWORD 7 = Right PAUSED
-fromDWORD 4 = Right RUNNING
-fromDWORD 2 = Right START_PENDING
-fromDWORD 3 = Right STOP_PENDING
-fromDWORD 1 = Right STOPPED
-fromDWORD x = Left $ "Unable to interpret " ++ printf "%x" x
-                  ++ " as a SERVICE_STATE."
-
-toDWORD :: SERVICE_STATE -> DWORD
-toDWORD STOPPED          = 0x00000001
-toDWORD START_PENDING    = 0x00000002
-toDWORD STOP_PENDING     = 0x00000003
-toDWORD RUNNING          = 0x00000004
-toDWORD CONTINUE_PENDING = 0x00000005
-toDWORD PAUSE_PENDING    = 0x00000006
-toDWORD PAUSED           = 0x00000007
-
-peekServiceState :: Ptr DWORD -> Script SERVICE_STATE
-peekServiceState ptr = do
-    dword <- scriptIO $ peek ptr
-    hoistEither $ fromDWORD dword
-
-pokeServiceState :: Ptr DWORD -> SERVICE_STATE -> IO ()
-pokeServiceState ptr sc = poke ptr . toDWORD $ sc
+module System.Win32.SystemServices.Services.SERVICE_STATE
+    ( SERVICE_STATE (..)
+    , nO_ERROR
+    , eRROR_CALL_NOT_IMPLEMENTED
+    , eRROR_SERVICE_SPECIFIC_ERROR
+    , peekServiceState
+    , pokeServiceState
+    ) where
+
+import Foreign
+import System.Win32.Types
+import Text.Printf
+
+import Control.Error
+
+nO_ERROR :: ErrCode
+nO_ERROR = 0
+
+eRROR_CALL_NOT_IMPLEMENTED :: ErrCode
+eRROR_CALL_NOT_IMPLEMENTED = 0x78
+
+eRROR_SERVICE_SPECIFIC_ERROR :: ErrCode
+eRROR_SERVICE_SPECIFIC_ERROR = 0x429
+
+-- | The current state of a service.
+data SERVICE_STATE = CONTINUE_PENDING | PAUSE_PENDING | PAUSED | RUNNING
+    | START_PENDING | STOP_PENDING | STOPPED
+    deriving (Eq, Show)
+
+fromDWORD :: DWORD -> Either String SERVICE_STATE
+fromDWORD 5 = Right CONTINUE_PENDING
+fromDWORD 6 = Right PAUSE_PENDING
+fromDWORD 7 = Right PAUSED
+fromDWORD 4 = Right RUNNING
+fromDWORD 2 = Right START_PENDING
+fromDWORD 3 = Right STOP_PENDING
+fromDWORD 1 = Right STOPPED
+fromDWORD x = Left $ "Unable to interpret " ++ printf "%x" x
+                  ++ " as a SERVICE_STATE."
+
+toDWORD :: SERVICE_STATE -> DWORD
+toDWORD STOPPED          = 0x00000001
+toDWORD START_PENDING    = 0x00000002
+toDWORD STOP_PENDING     = 0x00000003
+toDWORD RUNNING          = 0x00000004
+toDWORD CONTINUE_PENDING = 0x00000005
+toDWORD PAUSE_PENDING    = 0x00000006
+toDWORD PAUSED           = 0x00000007
+
+peekServiceState :: Ptr DWORD -> Script SERVICE_STATE
+peekServiceState ptr = do
+    dword <- scriptIO $ peek ptr
+    hoistEither $ fromDWORD dword
+
+pokeServiceState :: Ptr DWORD -> SERVICE_STATE -> IO ()
+pokeServiceState ptr sc = poke ptr . toDWORD $ sc
diff --git a/src/System/Win32/SystemServices/Services/SERVICE_STATUS.hs b/src/System/Win32/SystemServices/Services/SERVICE_STATUS.hs
--- a/src/System/Win32/SystemServices/Services/SERVICE_STATUS.hs
+++ b/src/System/Win32/SystemServices/Services/SERVICE_STATUS.hs
@@ -1,84 +1,83 @@
-module System.Win32.SystemServices.Services.SERVICE_STATUS where
-
-import Control.Applicative
-import Foreign
-import System.Win32.Types
-
-import Control.Error
-
-import System.Win32.SystemServices.Services.SERVICE_ACCEPT
-import System.Win32.SystemServices.Services.SERVICE_STATE
-import System.Win32.SystemServices.Services.SERVICE_TYPE
-
--- | Contains status information for a service.
-data SERVICE_STATUS = SERVICE_STATUS
-    { serviceType             :: SERVICE_TYPE
-    -- ^ The type of service. This binding only supports the WIN32_OWN_PROCESS
-    -- type.
-    , currentState            :: SERVICE_STATE
-    -- ^ The current state of the service.
-    , controlsAccepted        :: [SERVICE_ACCEPT]
-    -- ^ See 'SERVICE_ACCEPT' for details on this field.
-    , win32ExitCode           :: DWORD
-    -- ^ The error code the service uses to report an error that occurs when
-    --   it is starting or stopping. To return an error code specific to the
-    --   service, the service must set this value to
-    --   'eRROR_SERVICE_SPECIFIC_ERROR' to indicate that the
-    --   'serviceSpecificExitCode' member contains the error code. The service
-    --   should set this value to 'nO_ERROR' when it is running and on normal
-    --   termination.
-    , serviceSpecificExitCode :: DWORD
-    -- ^ A service-specific error code that the service returns when an error
-    -- occurs while the service is starting or stopping. This value is
-    -- ignored unless the 'win32ExitCode' member is set to
-    -- 'eRROR_SERVICE_SPECIFIC_ERROR'.
-    --
-    -- This binding does not support service-specific error codes.
-    , checkPoint              :: DWORD
-    -- ^ The check-point value the service increments periodically to report
-    --   its progress during a lengthy start, stop, pause, or continue
-    --   operation. For example, the service should increment this value as it
-    --   completes each step of its initialization when it is starting up. The
-    --   user interface program that invoked the operation on the service uses
-    --   this value to track the progress of the service during a lengthy
-    --   operation. This value is not valid and should be zero when the
-    --   service does not have a start, stop, pause, or continue operation
-    --   pending.
-    , waitHint                :: DWORD
-    -- ^ The estimated time required for a pending start, stop, pause, or
-    --   continue operation, in milliseconds. Before the specified amount of
-    --   time has elapsed, the service should make its next call to the
-    --   SetServiceStatus function with either an incremented dwCheckPoint
-    --   value or a change in 'currentState'. If the amount of time specified
-    --   by 'waitHint' passes, and 'checkPoint' has not been incremented or
-    --   'currentState' has not changed, the service control manager or
-    --   service control program can assume that an error has occurred and the
-    --   service should be stopped. However, if the service shares a process
-    --   with other services, the service control manager cannot terminate the
-    --   service application because it would have to terminate the other
-    --   services sharing the process as well.
-    } deriving (Show)
-
-instance Storable SERVICE_STATUS where
-  sizeOf _ = 28
-  alignment _ = 4
-  peek ptr = SERVICE_STATUS <$> (runScript . peekServiceType) pST
-      <*> (runScript . peekServiceState) pCS <*> peekServiceAccept pCA
-      <*> peek pEC <*> peek pSSEC <*> peek pCP <*> peek pWH
-    where
-      pST = castPtr ptr
-      pCS = castPtr ptr `plusPtr` 4
-      pCA = castPtr ptr `plusPtr` 8
-      pEC = castPtr ptr `plusPtr` 12
-      pSSEC = castPtr ptr `plusPtr` 16
-      pCP = castPtr ptr `plusPtr` 20
-      pWH = castPtr ptr `plusPtr` 24
-  poke ptr (SERVICE_STATUS st cs ca ec ssec cp wh) = do
-    pokeServiceType (castPtr ptr) st
-    pokeServiceState (castPtr ptr `plusPtr` 4) cs
-    pokeServiceAccept (castPtr ptr `plusPtr` 8)  ca
-    poke (castPtr ptr `plusPtr` 12) ec
-    poke (castPtr ptr `plusPtr` 16) ssec
-    poke (castPtr ptr `plusPtr` 20) cp
-    poke (castPtr ptr `plusPtr` 24) wh
-
+module System.Win32.SystemServices.Services.SERVICE_STATUS where
+
+import Control.Applicative
+import Foreign
+import System.Win32.Types
+
+import Control.Error
+
+import System.Win32.SystemServices.Services.SERVICE_ACCEPT
+import System.Win32.SystemServices.Services.SERVICE_STATE
+import System.Win32.SystemServices.Services.SERVICE_TYPE
+
+-- | Contains status information for a service.
+data SERVICE_STATUS = SERVICE_STATUS
+    { serviceType             :: SERVICE_TYPE
+    -- ^ The type of service. This binding only supports the WIN32_OWN_PROCESS
+    -- type.
+    , currentState            :: SERVICE_STATE
+    -- ^ The current state of the service.
+    , controlsAccepted        :: [SERVICE_ACCEPT]
+    -- ^ See 'SERVICE_ACCEPT' for details on this field.
+    , win32ExitCode           :: DWORD
+    -- ^ The error code the service uses to report an error that occurs when
+    --   it is starting or stopping. To return an error code specific to the
+    --   service, the service must set this value to
+    --   'eRROR_SERVICE_SPECIFIC_ERROR' to indicate that the
+    --   'serviceSpecificExitCode' member contains the error code. The service
+    --   should set this value to 'nO_ERROR' when it is running and on normal
+    --   termination.
+    , serviceSpecificExitCode :: DWORD
+    -- ^ A service-specific error code that the service returns when an error
+    -- occurs while the service is starting or stopping. This value is
+    -- ignored unless the 'win32ExitCode' member is set to
+    -- 'eRROR_SERVICE_SPECIFIC_ERROR'.
+    --
+    -- This binding does not support service-specific error codes.
+    , checkPoint              :: DWORD
+    -- ^ The check-point value the service increments periodically to report
+    --   its progress during a lengthy start, stop, pause, or continue
+    --   operation. For example, the service should increment this value as it
+    --   completes each step of its initialization when it is starting up. The
+    --   user interface program that invoked the operation on the service uses
+    --   this value to track the progress of the service during a lengthy
+    --   operation. This value is not valid and should be zero when the
+    --   service does not have a start, stop, pause, or continue operation
+    --   pending.
+    , waitHint                :: DWORD
+    -- ^ The estimated time required for a pending start, stop, pause, or
+    --   continue operation, in milliseconds. Before the specified amount of
+    --   time has elapsed, the service should make its next call to the
+    --   SetServiceStatus function with either an incremented dwCheckPoint
+    --   value or a change in 'currentState'. If the amount of time specified
+    --   by 'waitHint' passes, and 'checkPoint' has not been incremented or
+    --   'currentState' has not changed, the service control manager or
+    --   service control program can assume that an error has occurred and the
+    --   service should be stopped. However, if the service shares a process
+    --   with other services, the service control manager cannot terminate the
+    --   service application because it would have to terminate the other
+    --   services sharing the process as well.
+    } deriving (Show)
+
+instance Storable SERVICE_STATUS where
+  sizeOf _ = 28
+  alignment _ = 4
+  peek ptr = SERVICE_STATUS <$> (runScript . peekServiceType) pST
+      <*> (runScript . peekServiceState) pCS <*> peekServiceAccept pCA
+      <*> peek pEC <*> peek pSSEC <*> peek pCP <*> peek pWH
+    where
+      pST = castPtr ptr
+      pCS = castPtr ptr `plusPtr` 4
+      pCA = castPtr ptr `plusPtr` 8
+      pEC = castPtr ptr `plusPtr` 12
+      pSSEC = castPtr ptr `plusPtr` 16
+      pCP = castPtr ptr `plusPtr` 20
+      pWH = castPtr ptr `plusPtr` 24
+  poke ptr (SERVICE_STATUS st cs ca ec ssec cp wh) = do
+    pokeServiceType (castPtr ptr) st
+    pokeServiceState (castPtr ptr `plusPtr` 4) cs
+    pokeServiceAccept (castPtr ptr `plusPtr` 8)  ca
+    poke (castPtr ptr `plusPtr` 12) ec
+    poke (castPtr ptr `plusPtr` 16) ssec
+    poke (castPtr ptr `plusPtr` 20) cp
+    poke (castPtr ptr `plusPtr` 24) wh
diff --git a/src/System/Win32/SystemServices/Services/SERVICE_TABLE_ENTRY.hs b/src/System/Win32/SystemServices/Services/SERVICE_TABLE_ENTRY.hs
--- a/src/System/Win32/SystemServices/Services/SERVICE_TABLE_ENTRY.hs
+++ b/src/System/Win32/SystemServices/Services/SERVICE_TABLE_ENTRY.hs
@@ -1,29 +1,29 @@
-module System.Win32.SystemServices.Services.SERVICE_TABLE_ENTRY where
-
-import Control.Applicative
-import Foreign
-import System.Win32.Types
-
-import System.Win32.SystemServices.Services.Types
-
-data SERVICE_TABLE_ENTRY = SERVICE_TABLE_ENTRY
-    { serviceName :: LPWSTR
-    , serviceProc :: FunPtr SERVICE_MAIN_FUNCTION
-    }
-
-instance Storable SERVICE_TABLE_ENTRY where
-  sizeOf _ = 8
-  alignment _ = 4
-  peek ptr = SERVICE_TABLE_ENTRY <$> peek pServiceName <*> peek pServiceProc
-    where
-      pServiceName = castPtr ptr
-      pServiceProc = castPtr ptr `plusPtr` 4
-  poke ptr ste = do
-      poke pServiceName . serviceName $ ste
-      poke pServiceProc . serviceProc $ ste
-    where
-      pServiceName = castPtr ptr
-      pServiceProc = castPtr ptr `plusPtr` 4
-
-nullSTE :: SERVICE_TABLE_ENTRY
-nullSTE = SERVICE_TABLE_ENTRY nullPtr nullFunPtr
+module System.Win32.SystemServices.Services.SERVICE_TABLE_ENTRY where
+
+import Control.Applicative
+import Foreign
+import System.Win32.Types
+
+import System.Win32.SystemServices.Services.Types
+
+data SERVICE_TABLE_ENTRY = SERVICE_TABLE_ENTRY
+    { serviceName :: LPWSTR
+    , serviceProc :: FunPtr SERVICE_MAIN_FUNCTION
+    }
+
+instance Storable SERVICE_TABLE_ENTRY where
+  sizeOf _ = 8
+  alignment _ = 4
+  peek ptr = SERVICE_TABLE_ENTRY <$> peek pServiceName <*> peek pServiceProc
+    where
+      pServiceName = castPtr ptr
+      pServiceProc = castPtr ptr `plusPtr` 4
+  poke ptr ste = do
+      poke pServiceName . serviceName $ ste
+      poke pServiceProc . serviceProc $ ste
+    where
+      pServiceName = castPtr ptr
+      pServiceProc = castPtr ptr `plusPtr` 4
+
+nullSTE :: SERVICE_TABLE_ENTRY
+nullSTE = SERVICE_TABLE_ENTRY nullPtr nullFunPtr
diff --git a/src/System/Win32/SystemServices/Services/SERVICE_TYPE.hs b/src/System/Win32/SystemServices/Services/SERVICE_TYPE.hs
--- a/src/System/Win32/SystemServices/Services/SERVICE_TYPE.hs
+++ b/src/System/Win32/SystemServices/Services/SERVICE_TYPE.hs
@@ -1,55 +1,55 @@
-module System.Win32.SystemServices.Services.SERVICE_TYPE
-    ( SERVICE_TYPE (..)
-    , peekServiceType
-    , pokeServiceType
-    ) where
-
-import Foreign
-import System.Win32.Types (DWORD)
-import Text.Printf
-
-import Control.Error
-
-
--- | Win32 defines many types of services, but this binding only supports
--- WIN32_OWN_PROCESS.
-data SERVICE_TYPE
-    -- | The service is a file system driver.
-    = FILE_SYSTEM_DRIVER
-    -- | The service is a device driver.
-    | KERNEL_DRIVER
-    -- | The service runs in its own process.
-    | WIN32_OWN_PROCESS
-    -- | The service shares a process with other services.
-    | WIN32_SHARE_PROCESS
-    -- | Do no write your own services of this type. Windows Vista and above
-    --   prevent service processes from directly interacting with users.
-    --
-    --   A 'SERVICE_INTERACTIVE_PROCESS' is either a 'WIN32_OWN_PROCESS' or a
-    --   'WIN32_SHARE_PROCESS' running in the context of the LocalSystem
-    --   account which is allowed to directly interact with users.
-    | SERVICE_INTERACTIVE_PROCESS
-    deriving (Show)
-
-toDWORD :: SERVICE_TYPE -> DWORD
-toDWORD FILE_SYSTEM_DRIVER          = 0x00000002
-toDWORD KERNEL_DRIVER               = 0x00000001
-toDWORD WIN32_OWN_PROCESS           = 0x00000010
-toDWORD WIN32_SHARE_PROCESS         = 0x00000020
-toDWORD SERVICE_INTERACTIVE_PROCESS = 0x00000100
-
-fromDWORD :: DWORD -> Either String SERVICE_TYPE
-fromDWORD 0x00000002 = Right FILE_SYSTEM_DRIVER
-fromDWORD 0x00000001 = Right KERNEL_DRIVER
-fromDWORD 0x00000010 = Right WIN32_OWN_PROCESS
-fromDWORD 0x00000020 = Right WIN32_SHARE_PROCESS
-fromDWORD 0x00000100 = Right SERVICE_INTERACTIVE_PROCESS
-fromDWORD x = Left $ "Invalid SERVICE_TYPE: " ++ printf "%x" x
-
-peekServiceType :: Ptr DWORD -> Script SERVICE_TYPE
-peekServiceType ptr = do
-    dword <- scriptIO $ peek ptr
-    hoistEither $ fromDWORD dword
-
-pokeServiceType :: Ptr DWORD -> SERVICE_TYPE -> IO ()
-pokeServiceType ptr x = poke ptr . toDWORD $ x
+module System.Win32.SystemServices.Services.SERVICE_TYPE
+    ( SERVICE_TYPE (..)
+    , peekServiceType
+    , pokeServiceType
+    ) where
+
+import Foreign
+import System.Win32.Types (DWORD)
+import Text.Printf
+
+import Control.Error
+
+
+-- | Win32 defines many types of services, but this binding only supports
+-- WIN32_OWN_PROCESS.
+data SERVICE_TYPE
+    -- | The service is a file system driver.
+    = FILE_SYSTEM_DRIVER
+    -- | The service is a device driver.
+    | KERNEL_DRIVER
+    -- | The service runs in its own process.
+    | WIN32_OWN_PROCESS
+    -- | The service shares a process with other services.
+    | WIN32_SHARE_PROCESS
+    -- | Do no write your own services of this type. Windows Vista and above
+    --   prevent service processes from directly interacting with users.
+    --
+    --   A 'SERVICE_INTERACTIVE_PROCESS' is either a 'WIN32_OWN_PROCESS' or a
+    --   'WIN32_SHARE_PROCESS' running in the context of the LocalSystem
+    --   account which is allowed to directly interact with users.
+    | SERVICE_INTERACTIVE_PROCESS
+    deriving (Show)
+
+toDWORD :: SERVICE_TYPE -> DWORD
+toDWORD FILE_SYSTEM_DRIVER          = 0x00000002
+toDWORD KERNEL_DRIVER               = 0x00000001
+toDWORD WIN32_OWN_PROCESS           = 0x00000010
+toDWORD WIN32_SHARE_PROCESS         = 0x00000020
+toDWORD SERVICE_INTERACTIVE_PROCESS = 0x00000100
+
+fromDWORD :: DWORD -> Either String SERVICE_TYPE
+fromDWORD 0x00000002 = Right FILE_SYSTEM_DRIVER
+fromDWORD 0x00000001 = Right KERNEL_DRIVER
+fromDWORD 0x00000010 = Right WIN32_OWN_PROCESS
+fromDWORD 0x00000020 = Right WIN32_SHARE_PROCESS
+fromDWORD 0x00000100 = Right SERVICE_INTERACTIVE_PROCESS
+fromDWORD x = Left $ "Invalid SERVICE_TYPE: " ++ printf "%x" x
+
+peekServiceType :: Ptr DWORD -> Script SERVICE_TYPE
+peekServiceType ptr = do
+    dword <- scriptIO $ peek ptr
+    hoistEither $ fromDWORD dword
+
+pokeServiceType :: Ptr DWORD -> SERVICE_TYPE -> IO ()
+pokeServiceType ptr x = poke ptr . toDWORD $ x
diff --git a/src/System/Win32/SystemServices/Services/Types.hs b/src/System/Win32/SystemServices/Services/Types.hs
--- a/src/System/Win32/SystemServices/Services/Types.hs
+++ b/src/System/Win32/SystemServices/Services/Types.hs
@@ -1,10 +1,10 @@
-module System.Win32.SystemServices.Services.Types where
-
-import Foreign.Ptr (FunPtr, Ptr)
-import System.Win32.Types
-
-type HANDLER_FUNCTION_EX = DWORD -> DWORD -> Ptr () -> Ptr () -> IO DWORD
-type LPHANDLER_FUNCTION_EX = FunPtr HANDLER_FUNCTION_EX
-
-type SERVICE_MAIN_FUNCTION = DWORD -> Ptr LPTSTR -> IO ()
-type LPSERVICE_MAIN_FUNCTION = FunPtr SERVICE_MAIN_FUNCTION
+module System.Win32.SystemServices.Services.Types where
+
+import Foreign.Ptr (FunPtr, Ptr)
+import System.Win32.Types
+
+type HANDLER_FUNCTION_EX = DWORD -> DWORD -> Ptr () -> Ptr () -> IO DWORD
+type LPHANDLER_FUNCTION_EX = FunPtr HANDLER_FUNCTION_EX
+
+type SERVICE_MAIN_FUNCTION = DWORD -> Ptr LPTSTR -> IO ()
+type LPSERVICE_MAIN_FUNCTION = FunPtr SERVICE_MAIN_FUNCTION
