Well houdini, a geforce, and Win2000 work fine together. Although a little buggy but so is houdini 4. I have a friend who ran houdini on a tnt2 in a dual celeron in NT4 fine. Try turning off anti-aliased lines that might be the problem it is runing slow. I know in 4 it is defaulted to on, and with my configurations that made a big performance increase. The problem in NT is that houdini crashed trying to open the interface boxes. I can't even open the liceanse information with a geforce in NT. But i have no problem in 2000.