I've seen tweaking guides for WinXP/2000... try googling it. Basically, you can go in and disable just about every system service, and there are a few registry hacks you can do as well to disable even more stuff. I doubt this stuff makes *that* much difference except at the very high end of 3DMark01 (and maybe a few other benchmarks, like Quake3, which are highly CPU-limited). For something like 3DMark03, which is limited almost exclusively by your video card, it won't make much difference (if any).