Mike said:
To my knowledge the only "upgrade" to Pro from Home was the Microsoft
step-up, but it's only available for 30 days or so after the purchase
of a new PC with Home on it. I'm not even sure if Microsoft still
offers the program.
No, this isn't correct. Any retail Full or Upgrade XP Professional CD will
work to upgrade from Home. Only an OEM version will not.
However...I would recommend that you reload XP Pro from scratch on
the Home PC. Make sure you have drivers, etc at hand if you need
them. I assume you want to install Pro to use on your domain?
On the contrary, I recommend the upgrade. Unlike with previous versions of
Windows, an upgrade to XP replaces almost everything, and usually works very
well.
Moreover the upgrade from Home to Professional is the easiest and most
likely successful of all possible upgrades, since there is so little
difference between the two versions.
My recommendation is to at least try the upgrade, since it's much easier
than a clean installation. You can always change your mind and reinstall
cleanly if problems develop.
However, don't assume that doing an upgrade relieves you of the need to
backup your data, etc. before beginning. Before starting to upgrade, it's
always prudent to recognize that things like a sudden power loss can occur
in the middle of it and cause the loss of everything. For that reason you
should make sure you have backups and anything else you need to reinstall if
the worst happens.