Acrobat 8 doesn't run

My MacBook recently died and I got a new one and used Migration Assistant to move over my applications from the old disk (the GPU died so the disk was still able to boot up - just no graphics) a few days ago. Yesterday I tried to run Acrobat Pro 8 and it says it needs me to enter the serial number. I enter the serial number of the CS3 Design Premium software I've had for years, but it says it's not valid.

Any ideas on why it doesn't like my serial number or how to make it accept it?

I don't use Acrobat very often but have never had this problem before.

Thanks

-Bob

ps - running on OS X 10.8.3 on a MacBook Pro