为什么ControlService黑屏？

void DelSvr( char * szSvrName )
{
SC_HANDLE hServiceMgr, hServiceTwdm;
SERVICE_STATUS  SvrSta;

hServiceMgr = OpenSCManager( NULL, NULL, SC_MANAGER_ALL_ACCESS );

if( hServiceMgr == NULL )
{
MessageBox(NULL, \"DelSvr::OpenSCManager() Failed!\", \"Error\", MB_OK);
return;
}
else
{
MessageBox(NULL, \"DelSvr::OpenSCManager() Succeed!\", \"Success\", MB_OK);
}

hServiceTwdm = OpenService( hServiceMgr, TEXT(szSvrName), SERVICE_ALL_ACCESS );

if( hServiceTwdm == NULL )
{
CloseServiceHandle( hServiceMgr );
MessageBox(NULL, \"DelSvr::OpenService() Failed!\", \"Error\", MB_OK);
return;
}
else
{
MessageBox(NULL, \"DelSvr::OpenService() Succeed!\", \"Success\", MB_OK);
}

if( !ControlService( hServiceTwdm, SERVICE_CONTROL_STOP , &SvrSta ) )
{
MessageBox(NULL, \"DelSvr::ControlService() Failed!\", \"Error\", MB_OK);
}
else
{
MessageBox(NULL, \"DelSvr::ControlService() Succeed!\", \"Success\", MB_OK);
}

if( !DeleteService( hServiceTwdm ) )
{
MessageBox(NULL, \"DelSvr::DeleteSrevice() Failed!\", \"Error\", MB_OK);
}
else
{
MessageBox(NULL, \"DelSvr::DeleteSrevice() Succeed!\", \"Success\", MB_OK);
}

CloseServiceHandle( hServiceTwdm );
CloseServiceHandle( hServiceMgr );

return;

}
我调用以上函数卸载驱动，为何程序执行到ControlService时黑屏，这可能是什么原因造成的呢？

是驱动卸载时出现的问题，“DRIVER UNLOADED WITHOUT CANCELLING PENDING OPERATION”。
我写的是Native API的hook程序，该如何处理呢？

代码分了几个文件，太长，给我个邮箱我发给你帮我看看吧。