Guys no offence,

Spearhead, as I mention you earlier do a research. OK here is one of tech. website. I hope it will help you. If not go to google and do a research.

http://forums.techguy.org/windows-vista/540363-want-uninstall-vista-go-back.html

If you have any more problem, just let Nepalis community know about it.

Enjoy windows Xp