How to Log Off the Current User

Applications can use the ExitWindows or ExitWindowsEx function to log off the current user.

By default, when an application uses ExitWindows or ExitWindowsEx to log off, the system sends the WM_QUERYENDSESSION message to each window. Applications agree to terminate by returning TRUE when they receive this message. If any application returns FALSE, the log-off operation is canceled.

Windows NT: When an application returns TRUE for this message, it receives the WM_ENDSESSION message and it is terminated, regardless of how the other applications respond to the WM_QUERYENDSESSION message.

Windows 95: After all applications return TRUE for this message, they receive the WM_ENDSESSION and they are terminated.

To force all application to terminate, use ExitWindowsEx, and specify the EXW_FORCE flag. This prevents the system from sending WM_QUERYENDSESSION messages.

The system also sends the CTRL_LOGOFF_EVENT control signal to every process during a log-off operation. A console application can register a HandlerRoutine to process these messages.