How to disable the "Turn Off Computer" button in windows XP

Follow the given steps to disable Turn off Computer" button on the start menu:
To use this feature, you will need to be logged into your computer with administrative
rights.

Click Start button and type regedit in Run option then press Enter for next.
Here locate the location to:
HKEY_CURRENT_USERSoftwareMicrosoftWindowsCurrentVersionPoliciesExplorer
Here in right side panel, right click to create a new DWORD value with the name
NoClose.

Now close the registry editor and restart your computer after any changes to go into
effect.