Ed had to reinstall an old version of Windows and when he tried to authenticate it, it won't let him verify with a serial number. Leo says that's probably because Microsoft has discontinued the authentication server and turned it off. So he can't activate it, and it will expire in 30 days. There's probably a workaround though if he does a Google search. Microsoft really should keep it running for people like Ed. He may be able to call them and get it authenticated, but it may just be time to move on.