I read the software licening terms for windows vista and I think it said it is tranferrable http://download.microsoft.com/docum...lish_36d0fe99-75e4-4875-8153-889cf5105718.pdf "13. UPGRADES. To use upgrade software, you must first be licensed for the software that is eligible for the upgrade. Upon upgrade, this agreement takes the place of the agreement for the software you upgraded from. After you upgrade, you may no longer use the software you upgraded from." So I can install Vista upgrade from a OEM copy of Windows XP, and it will still be tranferable? Because when you install Vista, the Vista agreement overwrites the OEM windows XP copy, and now the new Vista agreement says it's tranferable.