Do this and forget the reinstall. Not necessary.
Part1
1. open the add/remove programs section and remove any 3DFX items.
2. open dislpay properties and go to the settings tab/advanced button/ adapter tab/change display button/display a list/show allhardware/standard display types/Standard Display adapter (VGA)
3. hit next and and say YES to the warning that pops up
4. hit next-finish-apply-close and restart when prompted
Part2 - After rebooting with standard vga adapter (do not reinstall voodoo if new hardware wizard pops up-just cancel that)
1.open regedit by going: Start/run and type "regedit" in the open box (no drive letters)
2. in regedit, open the 'HKEY_LOCAL_MACHINE/Software' folder and delete the '3DFX interactive' folder
3. then open the 'HKEY_CURRENT_USER/Software' folder and if you see a '3DFX interactive' folder, delete this one as well
4. then click on EDIT from the menu bar at the top of the regestery editor and click on "Find"
5. now, type in '3DFX' and hit "Find Next"
6. when it stops searching the registery hit the Delete key and say yes when it asks if you are sure
7. hit F3 to do a find next (only delete what it stopped on the first time-NOT everything listed with it)delete what it stops searching on
8. it is imporntant that you keep repeating this pattern each time it stops (Delete, Yes, F3). Delete everything it stops on no matter what it is. However, do not delete anything but the first thing it stops on when it halts its search or you could delete to much(stressed again). Let the registery editor search for each item, don't go looking 'willy nilly".
9. when regedit says "Finished searching through the registery" close it down and repeat steps 4 thru 8 at least 4 more times (it takes it a couple of shots to find it all)
10. repeat steps 4 thru 9 for the words 'Glide' and 'Voodoo' as well.
OK. You've removed the registery crap, now on to the driver files.
Part3
1. click Start/Find/Files or folders
2. make sure 'all files or folders' is set under advanced
3. look in C:\ (or wherever your windows directory is) making sure the 'include subfolders' box is checked
4. in the named box type 3dfx*.* and hit find now
5. delete any files that pop up
6. repeat using glide*.* and Voodoo*.*
Shut Down-Unplug-Ground Yourself and pop in the new card-boot up and load your new drivers-PLAY GAMES!!!!!!!!
This has worked for me without fail on many PC's. If it doesn't solve your problem, only one thing will. C: /s
Good Luck