Error Gaurd Good or Bad

Recently one my clients came to claiming that Error Guard had fixed his slow and freezing start up problems that he was having. (Which were non existent when I build the machine.) I told him that I’ve heard error guard causes more problems than it fixes and is a source of spyware. I also heard it?s the greatest thing since sliced bread. I don’t think I can change his mind at least until it breaks down totally but for my own information what’s the really story on ErrorGaurd. Also what could be causing startup freezes or slowdowns? Stops on the Windows XP logo screen with the blue loading bar underneath. Thanks for your opinions, comments and answers to these questions.