I recently bought a new computer and when I try to download PC2 (1.01.10) it tells me my serial number is invalid. Is there an expiration for the base game?

Not sure if this is the place to post it, but, I feel a need to recognize a generous and magnanimous act. Without going into too much detail, a couple of months ago I placed an order (Panzer Korps and the '39 campaign) with Matrix. I received notice the order had shipped and then USPS dropped the ba...