LOL, I suggest to do that..
I got my ATI Radeon today and installed older drivers, those didn't like of DX8 and gave wrong resolution/hz for my monitor which rejected the image and went blank.
I had to go in safe mode and install up to date drivers which worked with DX8.
Funny that with TNT2 I didn't experience problems between DX7 and DX8 when installing different driver versions.