Unregisters a function from being called with imaging-specific data.
BOOL WINAPI WIMUnregisterMessageCallback( HANDLE hWIM FARPROC fpMessageProc );
Parameters
hWim
[in] The handle to a .wim file returned by WIMCreateFile.
fpMessageProc
[in] A pointer to the application-defined callback function to unregister. Specify NULL to unregister all callback functions.
Return Value
If the function succeeds, then the return value is nonzero.
If the function fails, then the return value is zero. To obtain extended error information, call the GetLastError function.