I have a dual 800PIIIs w/ 768megs of ram. 'ME' does not recognize multiple processors. It was also slower that 98. 2000 was great, this is some applications that do not work on it though (Porsche Unleashed) unless you trick the program into thinking it is on a 9x machine. So far I have had no problems with XP. Looks sweet and is optimized for things like digital cameras. Somethings like adaptec cd will need to be patched to work but for the most part the is a lot of driver support out there.