It's hard to say. This is the main drawback of not being able to actually see your computer. I do what I can, through our correspondence here on the internet. The next logical step would be to use a "real" XP CD. However, your problem may end up being hardware related. The reason I asked if you posted the right stop error earlier is that web gives many different causes for this particular error - service pack 3 being the most popular.
There are a lot more knowledgeable people than me on this forum. Hopefully, one of them will chime in soon.
By the way, did you dust out your computer?