http://www.falconfly.de/banshee.htm

The BansheeTeam and Evolution Drivers should work fine for Win9x, the Evolution Driver series is best suited for Win2000/XP.

After you uninstalled your old Driver, installing the new one is as easy as executing the Setup file, shouldn't be too complicated as no Problems are expected during installation.

As Diabolo 2 is a very old Game, it might require original (old) Glide Files in order to run however; you'll have to test which Driver suits your favorite Game collection best.

Not sure what you mean, but that might be the Control Software like the 3dfx Tools (original) or VoodooControl (3rd Party).

But these won't solve your Problem, it is the Driver itself that takes care of how well Games run; the 3dfx Tools only allow to specify certain settings that can somewhat optimize the Visual Quality and/or Performance, for example.

If you're is clocked lower, then yes, it would overclock it.

If unsure what your Model is clocked at or unfamiliar with modifying the .inf File yourself, it is best to choose another Driver.

(?)

There shoudn't be any searching involved, either just hit the Setup Executable (if present), or manually update the Driver via Device Manager.