If you use IPX protocol on your network normally, uninstalling and then reinstalling the drivers will fix the problem. If you don't, just go ahead and remove them. A 3d accelerator card is designed for very fast rendering of shapes to the screen, on a separate chip from your main processor, allowing for more and better graphics while letting your computer do more with robots and sound and other exciting stuff. Many cards these days and many newer computers have 3d hardware support, but not all of them. Here is a list of supported cards and the website where you can get the latest reference drivers for them.
Software rendering is unfortunately just too slow to be playable. .
The ge-force has not been tested extensively with d3 but should work. Generally direct3d mode is more stable with these cards. Turn on bump mapping with the -bumped command line argument. This is a legacy card from before stb was bought by 3dfx. Try using the -superlowmem flag to help compensate for the lower ram.