The ExitWindowsEx function either logs off, shuts down, or shuts down and restarts the system. BOOL ExitWindowsEx(UINT uFlags, DWORD dwReserved); uFlags specifies the type of shutdown. EWX_SHUTDOWN = 1 Shuts down the system to a point at which it is safe to turn off the power. All file buffers have been flushed to disk, and all running processes have stopped. EWX_REBOOT = 2 Shuts down the system and then restarts the system. EWX_FORCE = 4 Forces processes to terminate. Windows does not send the messages WM_QUERYENDSESSION and WM_ENDSESSION to the applications currently running. Therefore, you should only use this flag in an emergency.