|I was trying to find any part of the XP EULA that says you can't upgrade to XP with another upgrade; it seems like you would be violating the license without at least having full software somewhere (installed or software).|
This is all the EULA has under upgrades:
"UPGRADES. To use Software identified as an upgrade, you must first be licensed for the software identified by Microsoft as eligible for the upgrade. After upgrading, you may no longer use the software that formed the basis for your upgrade eligibility."
Right now, I only have an old Windows ME upgrade CD and a XP upgrade CD, and no full software.