If you dont want any users to change desktop settings ,then follow these steps:
>>Open registry editor(Start>Run>regedit)
>>Open registry editor(Start>Run>regedit)
>>Navigate to the following key:HKEY_CURRENT_USER\Software\Microsoft\WindowsNT\CurrentVersion\ProgramManager\Restrictions
>>Create or edit the DWORD NoSaveSettings. Now to disable saving desktop settings, set its
value to 1.
>>Reboot your PC for setting to take effect.
Thats all U R done!!!