To remove the "Log Off user" entry from your Start menu

To remove the "Log Off user" entry from your Start menu:

1. Start the Registry Editor
2. Go to HKEY_CURRENT_USER \ Software \ Microsoft \ Windows \ CurrentVersion \ Policies \ Explorer
3. Right-click an open area in the right pane and select New > DWORD Value
4. Name it NoLogOff
5. Double-click this entry and add the value 1
6. Exit RegEdit and restart Windows

To put "Log Off user" back on the Start menu, simply rename the value to 0.

This can also be done using TweakUI (you can find it on your CD-ROM in the \tools\reskit\powertoy folder).
Click on the IE4 tab, and remove the check mark from the Allow logoff box