I want to prevent users from shut down or restart the system. my application runs as a Win32 Native Service (written by C++) and under LocalSystem account.
I heard about WM_QUERYENDSESSION it's solution: creating a hidden window and capturing WM_QUERYENDSESSION to prevent shutdown.
but this solution is not really clean and also have to create one window for each desktop. So i have to enumerate desktops and also care about when a desktop created/destroyed. All of these make the situation nasty!
Is there any way to detect shutdown/restart event and prevent system shutdown/restart?
(It is not important that the event is shutdown or restart, both of them must be cancelled!)
You can't.
Because allowing programs to prevent shutdown/restart would be somewhat of a security vulnerability, don't you think?
If the user tells the system to shutdown or restart, that's what's going to happen.
BTW, WM_QUERYENDSESSION is passed when the current user is logging out of Windows. It's a notification, nothing more, and if you're using it in any other way then you're using it wrongly.