Boot Freeze-Up

I have a computer that was barely used and one day it just crashed. It came to the XP progress bar boot-up screen and froze. It has done this ever since, you cannot log-in at all, no safe mode, no nothing. What makes it even more of a problem is that I reinstalled windows xp pro, and when it got to the install screen it froze there too. So now, I am in the middle of an xp install that won’t finish. Even more…I tried to run ERD Commander, and it freezes up as well – this is just running from the CD. Do I have a mobo problem? Or is it something else?