A fresh install can be a lot of work, with drivers and reinstalling all programs.
What I would like to do is if you are able make a full backup image of it currently and save that image to an external drive.
The you wipe xp and install fresh. See if everything is fixed. If not we put back the image and the system to what it was before the reinstall.
If it fixes it then we know the virus was too deep and this was the only way (Or at least easiest way) to fix it. If it still have blue screen problems then we know it is hardware related
If you are not able to do this we can keep digging and see what we can do
Shane