XP is quite ok to run on older machines. all you need is a fast hard drive and most of the lag time will be taken care of. Memory would be great as well. I have an old HP P3 500 mhz bad boy. IT has 256 mb of ram a geforce 2 64 mb vid card and while it doesnt exactly keep up with the other high end machines, it holds its own for everything you can throw at it. This is not nLited btw. If it is nLited I can see it unleashing more performance and that is quite impressive I think. XP is bloated I agree but it is quite friendly on the hardware.