Could also be that some part of your old drivers are still there. Did you remove them before installing your new cards?
Check under add/remove programs and see if they are still listed there.
My gaming machine:
P4 2.8 GHz
2 X 512 MHz PC3200 in dual DDR mode
Intel D865PERL MOBO
integrated 6.1 MAX audio
Logitech duo MX mouse and KB
ATI RADEON 9800 PRO