Disabling Shutdown In Windows XP

1. Open Registry Editor. This can be done by clicking on Start button, selecting Run, inputting regedit and clicking on OK button.
2. Go to HKEY_CURRENT_USER/Software/Microsoft/Windows/Current Version/Policies/Explorer.
3. Right click on the pane on right and create a new String Value. Rename it to NoClose and put its value to 1.
4. Go to Task Manager.
5. End the process named Explorer.exe under the Processes tab.
6. Under Applications tab, select new process and type Explorer.exe in the dialog box that appears and click on OK.
7. Your Shut Down button has been disabled and your computer wont close until you do something drastic.
8. To enable shut down again, change the value of NoClose to 0 and restart the Explorer.exe process again.