Shutdown shortcut for Windows 8

Create a shortcut on your desktop (right-click, go to New, then Shortcut). Enter "shutdown.exe /s /t 00" as the location of the item, and press Next. Now name the shortcut (prefereably "Shutdown") and press Finish.

Right-click the shortcut, and navigate to Properties. Choose Change Icon in the Shortcut tab, and then OK to leave the warning box. Choose an icon of your choice from the list. In the screenshot above, you'll see we chose a Power button.

Right-click the shortcut again, and select Pin to Start. You can place the icon on your Start screen wherever it's convenient. Clicking it will instantly shut down your computer.

For shutdown : shutdown.exe /s /t 00

For restart : shutdown.exe /r /t 00

For Hibernating: shutdown.exe /h