jt3 said:
What, explicitly, are the differences between the retail and upgrade
versions of XP Pro? Both in terms of capabilities,
They are identical.
and transferability to a new machine?
They are identical. Either can be transferred as desired.
Both the Full and Upgrade versions can do either a clean installation or an
upgrade installation. The only difference between the two is that to do a
clean installation with the Upgrade version requires that, as proof of
ownership, you insert a previous qualifying version's CD when prompted to do
so.
Further, what is necessary to
qualify for the upgrade?
Windows 98, 98SE, or Me. You can also use a Windows 95 CD as proof of
ownership, but you can not upgrade over the top of Windows 95. If you are
upgrading to Windows XP Professional (but not XP Home), Windows 2000 also
qualifies.
Note that the above essentially means that a Windows XP Upgrade version plus
a copy of Windows 98 is essentially as good as a copy of the Full version.
Since that combination is much cheaper than the Full version (a used copy of
Windows 98 can be bought very inexpensively on eBay), that's what I
recommend. Also note that that combination of the Upgrade plus 98 is usually
only slightly more expensive than an OEM copy, and comes without the OEM
copy's restrictions, it's a better deal than an OEM copy too.