Stop Users Changing Desktop Settings

If you are running a cyber cafe (or a public machine) and do not want users to change desktop 

settings,

• Navigate to the following key: 
  HKEY_CURRENT_USER\Software\Microsoft\WindowsNT\CurrentVersion\ProgramM
  anager\Restrictions. 
• Create or edit the DWORD NoSaveSettings. 
• Now to disable saving desktop settings, set its 
  value to 1. 
• Reboot the machine for the settings to take effect.

NOTE :- Take the backup of your registry (by one of these Software's) before doing any tweak.