Restriction Error

I have a friend who had a hard drive fail. He replaced the drive and restored everyhing back to the way it was before. He loaded Tweak for power users. He disabled logoff from the start menu. Then he restarted his PC. He decided to remove Tweak for power users (without changing the settings back to original before installing Tweak…) then he restarted again and started having problems.
There was a dialog box named restrictions. It said “You are being restricted from processing this operation. Please contact system Administrator”. He then tried to reinstall tweak… but he was not able to execute any .exe or .bat files so he is pretty much stuck. Does anyone have any ideas???