Re: GeForce 2 MX with personality issues
If you put an ATI card in and loaded drivers to debug system, then put Nvidia card back in, it might be a driver conflict.
I would delete video card drivers, boot to safe mode and run Driver Cleaner 3 (found @guru3d.com) to remove old ATI and/or Nvidia leftover driver files, then reboot and reinstall some newer Nvidia drivers.
If its not driver conflict then maybe its time for a new video card. Lots of cards much better than GF2 MX out now for very little money.
If this problem is because you flashed to wrong bios or one thats not compatible, you may not be able to salvage the card and it will need replacement.