I bought xp home and installed it then I bought xp professional and I want to
install it on the computer I installed xp home. I want to use the xp home on
another computer how do I install xp professional and uninstall xp home so I
can use the product key for xp home again?
A couple of points:
1. Did you buy Retail copies or OEM copies? If the former, just
reinstall to your liking. But if the latter, be aware that one of the
major disadvantages of OEM versions (and the reason I recommend
against getting them) is that their EULA permanently ties a copy to
the first machine it's installed on; it may never be reinstalled on
another.
2. Why do you want/need Professional on either machine as opposed to
Home? XP Professional and XP Home are exactly the same in all
respects, except that Professional has a few features (mostly related
to networking and security) missing from Home. For most (but not all)
home users, even those with a home network, these features aren't
needed, would never be used, and buying Professional instead of Home
is a waste of money. In general, unless you need to join a domain, you
probably don't need Professional.