I have a Lenovo box with OEM Vista and store-bought Win7 upgrade. Wondering though, if I upgrade that box can I "remove Win7" and go back to OEM's Vista ( just curious) and perhaps use that Win7 upgrade on another XP, Vista box instead ? I got the Lenovo as a freebie that didn;t boot so I ordered restore CDs and it's fine now. I've never used the Lenovo box for anything yet. Thinking of using that just for media and if not much difference between Vista/Win7 maybe I'd like to upgrade an XP box instead ??