You will need to get a CD of the previous OS. Doesnt matter if you own it, or if it's Win98, ME, 2000. During setup of XP, you'll need to pop in the said CD when it asks you to. Thats it.
goldeagle2005 33 Finkus Stinkalotus Team Colleague
goldeagle2005 33 Finkus Stinkalotus Team Colleague