Shutdown by timer

Now the window that opens you to write the following line
shutdown -s -t 00


When in fact at 00 you can take a few seconds after you click the shortcut through the Our computer turns off by itself.
 You can for example write 30 then it will be within 30 seconds

And this window click on Finish

Now when you want to turn off the computer
Just click on the shortcut way we've created, and computer Itcva alone at the end ofthe time we told him.

Good luck