Ich zitiere mal das
msdn:
Zitat:
Return Value
If the function succeeds, the return value is a
handle to the newly created
mutex object.
If the function fails, the return value is NULL. To get extended error information, call GetLastError.
If the
mutex is a named
mutex and the object existed before this function call, the return value is a
handle to the existing object, GetLastError returns ERROR_ALREADY_EXISTS, bInitialOwner is ignored, and the calling thread is not granted ownership. However, if the caller has limited
access rights, the function will fail with ERROR_ACCESS_DENIED and the caller should use the OpenMutex function.
Was liefert GetlastError?