Windows XP: Computer startup problem

Computer startup problem

Hi, i installed windows xp on an older computer (windows 98 era) and i'm a pretty advanced computer dude. One day when my computer started up (i added no hardware at all) as soon as it started a window popped up and said "The software for your hardware requires you to restart your computer" or something like that. So I did, and it goes through normal startup, blanks the screen, then starts over at the computer startup screen. I have used system restore in safe mode to bring it back, but the window keeps popping up, and even if I push no, as soon as the computer turns off, it's doomed to keep looping at startup. I have narrowed it down to that indeed it is a driver problem, the one that gives me that window. Any ideas on how to find out what driver it is would be helpful, I can't figure out what it is.