Here's the thing. My son (away at school) bought a used PC from a fellow student. It seems now the the XP pro O.S. is an unregistered copy. I suppose a more savvy user would have been wary of this problem from the outset. I've since learned that bootleg copies of XP pro are not all that rare, but the fact remains that he now owns a computer with illegal software. My questions are these; Does he (I) have to buy a full retail version of XP to replace the bogus copy? OR can we buy an OEM version, OR can we buy an XP upgrade? Naturally I don't want to spend more than necessary to fix this problem, but more than that, I want to do what's legally and ethically proper. There may be a life lesson in here somewhere, I just hope it's not a $300 life lesson. If we solve this deli ma, my next question involves how to install the new operating system, but I think best to tackle one issue at a time. Thanks!