Ben wrote:
just uninstall the nvidia drivers via add/remove and reboot
shut down - swap cards - reboot
install 3.7 cats (the most stable and bug free for most ppl)
you can always try 3.9s later and if they give problems then role
back to
3.7
the cats include smartgart for adjusting agp - just check the setting
matches what youve set in the bios.
enjoy

We see many problems in this newsgroup with NVidia users that ONLY uninstall
NVidia drivers and switch to ATI cards... If i were the OP, i would indeed
use some registry cleaner... Myself, i usually reinstall windows after i
swap a MAIN component (vid card/mainboard)

THomas.