About a month and a half ago I built a new system for my Dad and younger brother to share after the motherboard went on their old one. I set everything up for them exactly how they each wanted it, since I knew how picky they both are when it comes to the way their desktop and start menu are set up and the options in their various programs. Anyways, it's XP Pro (as made half obvious by the category I'm posting this in) and my Dad has an account in the admin group and my brother is just in the users group, so it's a "Limited Account". As with most younger brothers, he has a tendency to do annoying things, and he waits until my Dad leaves the room for a few minutes without logging off and makes himself an administrator as well. I need a way to stop this because he has a horrible record for installing spyware and getting viruses and causing all sorts of other havoc. So is there an easy way to keep him from modifying the group he's in? Any solution would be extremely helpful.