1. Download 'Driver Cleaner' (NOTE, the ORIGINAL version - NOT the PRO or V3 versions!)
[I don't think it's available anymore! PM me your email addy. and I'll email it in a ZIP to you]
2. Download 'Reg Cleaner'
http://www.worldstart.com/weekly-download/archives/reg-cleaner4.3.htmUNINSTALLATION
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1. Uninstall drivers as usual.
2. Reboot PC when prompted.
3. Go to SAFE MODE
4. Run Driver Cleaner on the '3dfx' profile and click 'clean'...wait till it's finished.
5. Run CAB Cleaner (part of driver cleaner) and wait till it is finished [may take a while!]
6. Run Reg cleaner and click the 'Author' column to sort registry entries by alphabetical order.
7. Look for any entries by '3Dfx' and select them.
8. Click 'Remove Selected' and wait till it's finished.
Your system is clean of the old drivers, now reboot and install the new ones!