My friend showed me on her laptop how she can tell when someone turns on her laptop & even when someone attached a little thumb drive & copied files to the drive. I have tried to find this on my computer (a Dell PC with Microsoft XP Professional) but I can't find this information. I think someone is logging on to my computer & copying files. I can't password protect it because I share it. I believe this happens after we have gone. I'd appreciate if anyone can tell me how to solve this mystery.