"I have tried ot install the Adobe product on the new drive but unfortunately I have mislaid the Product Key"
--- Does that mean you haven't been able to actually install it?
--- If that's the case then I don't see how nirsoft, belarc or that prior program that reports those 4 digits will be able to help you
--- That program that reported the first 4 digits might be starting of a generic portion of a product key but I don't see how they can find the rest of the product key if the program isn't at least installed
But in case I'm wrong
Malwarebytes quarantined the nirsoft you tried earlier
--- Can you temporarily disable Malwarebytes and try nirsoft again?
I would try belarc one more time if that doesn't work
Did your local computer shop indicate whether or not they have a program that will find your product key?
--- It sounds to me like that application is important enough to pay to acquire the product key