How to Cancel a Windows Shutdown, Reboot, or Log off?

Sometimes, by mistake, you press the shutdown, restart, or log off button which may result in a loss of all your unsaved documents or data. You may cancel this action, but beware, you must be very fast!

•  In Start> Run, type the following command quickly:

                 shutdown -a

• Or, you can press simultaneously the windows button + R button and type the above command.