Remove shutdown option from "Turn off computer"

Here is a little trick to play with your friend,which is by removing the shutdown option from start menu in their computer.
Just hack it down !!!.Follow the steps :
Go to start, then run then type "regedit" and press enter. Then try to find out the following key:

HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer
"NoClose"="DWORD:1"


But remember every time to back up registry so that in case of any problem after applying any trick you can return back to the previous form without hampering any system.Sp always backup your registry.