not booting, screen goes nuts, etc

A friend of mine's having annoying probs.
Sometimes it won't boot to the bios or anything, and if it boots, screen goes nuts. He's using an old *** S3 Trio 64 pci card, but he says if he doesn't boot in safe mode, it freezes.
He's got a Ti4200, says windows loads fine, detect drivers and stuff, but when he installs nvidia's drivers, it goes scrammbly after reboot. He tried every driver, the ones that came in cd, lastest ones and old ones, still no go.
We're going for a fresh install, clear CMOS and all that crap. Any suggestions?

If this is the same machine but different cards there is a possibility that the previous drivers are causing the problem. I am not an expert when it comes to these things but I am sure you will get plenty of replies. I would try to remove all previous traces of the old drivers then install the windows generic drivers reboot then install the nvidea drivers. A fresh install would be a last resort for me but I also love the feeling of a fresh install so if it has been a while it might be a good time for it. Good Luck