Currently Being ModeratedMar 17, 2013 10:33 AM (in response to Appatight)
I don't know of a way to retrieve a lost serial number or get around it. You might try one of your local schools that run Mac servers but no longer run 10.4. You could ask them to transfer/donate one of their old 10.4 serial numbers to you. It wouldn't hurt your case if you still had the original receipt. There may be other ways, I just don't know of any.