Comp crashes when I try to run a game w/ new gefor

OK, I got my geforce 4 card about 2 weeks ago (ti4200, xtasty 128mb). It played games flawlessly up until today.

Now, every time I load a game or anything requiring 3D/extra acceleration, it tells me that the drivers are incorrect/the device is faulty and restarts the PC (blue screen of death).

So, I tried to roll back the drivers, update the drivers from the rolled back drivers, uninstall the drivers totaly and install the ones that came with the card.. etc. etc. etc.

Nothing changed. I keep getting the windows XP "System has recovered from a serious error" messages, but it hasn't recovered. It's pissing me off.

I have been messing around with SOME stuff because my RAM isn't operating at 133mhz like it should be. I had been going into BIOS and changing things, but nothing drastic. Then when this started happening, I had it reload defaults into BIOS.. no difference.

Any help would be GREATLY appreciated. I'll keep trying to figure this out.

If this seems like a big problem that can't easily be fixed, would it work just to reformat my hard drive and start from scratch w/ everything? I wouldn't mind doing that too terribly much, but I'd like some feedback as to if that would solve my problems. Thank you!

system specs:
1.2ghz amd tbird
256mb sdram
a7v mainboard
geforce4 ti4200 visiontek xtasy
windows xp home