I haven't had enough coffee yet for this one! :P Ok, it sounds like you either somehow restore another devices data that had a password on it or somehow inherited an IT policy that was lurking on the PC. Is it a work issue PC?
Is it just the Media Card that you can't access or the entire device?
Worst case scenario is that after the 10th attempt (or less depending on setting) the phone will be usable again but all data will be lost. Actually, I think the data on the Media Card may still be there but you'd better wait for others to comfirm.
Sorry and good luck!