I just received the weirdest message after upgrading my monitor on my windows XP; "Since windows was first activated on this computer, the hardware has changed significantly. Due to these changes windows must be reactivated within 3 days. Do you want to reactivate windows now?" I have no product key as this computer was sold to me. Do any of you guys know how to get around this issue? Google hasn't been much help so far but I will keep looking for an answer.