So currently your using Xp?. This problem seems to be I'm not certain though
AGP Graphics cards.
I've read that someone actually solved there problem by
removing the agp card and put a PCI video card in the computer. The computer should boot fine. delete amdagp.sys, turn off the computer, put the agp video card back in, and turn the computer back on.
If you've not got another graphics card to try it with then we'll have to find another solution

,
Looking forward to your reply
Bugsey.