Hacking Shutdown

you can disable shutdown option of your friends or any computure.If you do this they can't shut down their pc with normal process.To disable shutdown option:

• open registry editor by writing regedit in run commandl
• Go to HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies\Explorer. (In Vista,you may need to create the Explorer key.)
• Create a new DWORD value named NoClose with a data
  value of 1
• Exit the Registry, and reboot for the change to take effect

Now you won’t be able to shut downWindows in the normal manner. You’ll have to run Task Manager by pressing Ctrl-Alt-Del and then using the Task Manager’s ShutDown menu to close Windows.
If you want to reenable normal shutdowns, delete the NoClose value.

NOTE:Under Vista, this setting may not take effect until you shut down and start Windows back up.