Have office 2000 disc – lost product key

I should have known better – but even experts in the field get it wrong!!

I have an office 2000 disc (bought and paid for) but have mislaid the product key.

I had a product key written down, and thought this was it, but the install says it’s not valid.

Just my luck.

Does anyone know how to get the product key from the install disc?

Much appreciated.

Kind Regards
John