go to control panel > system > device manager > display adapter > 'your gfx card' > delete.
then u will have no drivers and when u reboot your comp will re detect the card and propt you to install drivers.
download the older drivers first of course.
if you're getting sys dumps - it is a map problem. the best solution to this is a fresh install of DFLW. just makesure you save any maps you want to keep beforehand
