I changed to XP earlier this year: I'd got so much bits and rubbish on the C: drive that booting up was taking forever so I took the plunge to Format C: and install XP from the ground up. Only problem was I assumed I would be able to re-install software I'd got the original discs of, so didn't include them in the back-up. Have now got useless discs of Norton Anti-Virus, Music Works, Visio, etc. that XP won't install!
(apart from that, the stuff that did install seems to work fine)

Ho hum
nick