Well actually it does but I couldn't think of a title quick enough :P
Thanks Bunnios who sent me a screenshot of the Windows XP SP1 installing. So what! I hear y'all cry, well.. the difference is that this screenshot captured the first few seconds of install where it validates your product key!
What the implications or outcome of such an action is as yet unknown. but this poster imagines a successful install followed by a lock-down. I think that blocked keys might be a simple block of further upgrades. I have a legit version so its difficult to test ;-)
I can't imagine Microsoft locking you out of your system, it would be asking for trouble where humans make mistakes and valid keys might get locked out.
Until Windows 2000 (or the 2000/Millennium titles) pirates got off scot free. These days Microsoft are increasingly validating their software which makes me wonder about the support implications for years to come. Can we still activate our XP license in 5 years from now? Only time will tell how that is handled.
Screenshot: Windows XP SP1 checks the Product Key prior to install