if no one here can figure it out, probably best to get yourself a second hard disc, set it up as 2000, transfer all your files over, make sure all is working and then gradually reinstall everything on the Xp disc until you get it all working
but 2000 works fine and i dont think Xp will make you anymore money! so why not stick with 2000, if you cant trade at the moment, this must be a very expensive upgrade attempt
would have been a lot cheaper to get a new computer already loaded with XP and get it working whilst you carry on trading with the old one, and then swop over