The ExitWindowsEx function either logs off the current user, shuts down the system, or shuts down and restarts the system. It sends the WM_QUERYENDSESSION message to all applications to determine if they can be terminated.
BOOL ExitWindowsEx(
UINT uFlags, // shutdown operation
DWORD dwReserved // reserved
);
| Value | Meaning |
|---|---|
| EWX_LOGOFF | Shuts down all processes running in the security context of the process that called the ExitWindowsEx function. Then it logs the user off. |
| EWX_POWEROFF | Shuts down the system and turns off the power. The system must support the power-off feature. Windows NT: The calling process must have the SE_SHUTDOWN_NAME privilege. For more information, see the following Remarks section. |
| EWX_REBOOT | Shuts down the system and then restarts the system. Windows NT: The calling process must have the SE_SHUTDOWN_NAME privilege. For more information, see the following Remarks section. |
| EWX_SHUTDOWN | 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. Windows NT: The calling process must have the SE_SHUTDOWN_NAME privilege. For more information, see the following Remarks section. |
This parameter can optionally include the following values:
| Value | Meaning |
|---|---|
| EWX_FORCE | Forces processes to terminate. When this flag is set, the system does not send the WM_QUERYENDSESSION and WM_ENDSESSION messages. This can cause the applications to lose data. Therefore, you should only use this flag in an emergency. |
| EWX_FORCEIFHUNG | Windows NT 5.0 and later: Forces processes to terminate if they do not respond to the WM_QUERYENDSESSION or WM_ENDSESSION message. This flag is ignored if EWX_FORCE is used. |
If the function succeeds, the return value is nonzero.
If the function fails, the return value is zero. To get extended error information, call GetLastError.
The ExitWindowsEx function returns as soon as it has initiated the shutdown. The shutdown or logoff then proceeds asynchronously.
During a shutdown or log-off operation, applications that are shut down are allowed a specific amount of time to respond to the shutdown request. If the time expires, the system displays a dialog box that allows the user to forcibly shut down the application, to retry the shutdown, or to cancel the shutdown request. If the EWX_FORCE value is specified, the system always forces applications to close and does not display the dialog box. If the EWX_FORCEIFHUNG value is specified, the system forces hung applications to close and does not display the dialog box.
Console processes receive a separate notification message, CTRL_SHUTDOWN_EVENT or CTRL_LOGOFF_EVENT, as the situation warrants. A console process routes these messages to its HandlerRoutine functions, which are added and removed by calls to the SetConsoleCtrlHandler function. ExitWindowsEx sends these notification messages asynchronously; thus, an application cannot assume that the console notification messages have been handled when a call to ExitWindowsEx returns.
Windows NT: To shut down or restart the system, the calling process must use the AdjustTokenPrivileges function to enable the SE_SHUTDOWN_NAME privilege. For more information about security privileges, see Privileges.
Windows 95: ExitWindowEx does not work from a console application, as it does on Windows NT.
Windows NT: Requires version 3.1 or later.
Windows: Requires Windows 95 or later.
Windows CE: Unsupported.
Header: Declared in winuser.h.
Import Library: Use user32.lib.
System Shutdown Overview, System Shutdown Functions, AdjustTokenPrivileges, HandlerRoutine, SetConsoleCtrlHandler