AFAIK I know with Windoze, if you got it with the PC, you can sell the PC with Windoze, and you aren't supposed to install it on any other computers (of course, XPee enforces this). If you bought the crap separately, you can sell it however you like. If you got a pirated corporate version, well, then you can't sell it you should just be quiet, that shop owner looks like the kinda guy that'd love to squeal to M$ on ya. He won't take the computer 'naked' (i.e., with no OS), will he? If he was reputable, that's the only deal he'd settle for in case of any licence shit. Then he'd get a new licence from M$, or put a desktop Linux distribution on it for $0. But if this is a pawn shop, why does he give such a shit about what OS is on it?