Bought this game a long time ago. I have now purchased a new computer, and used the old install on the new computer. But I have no idea what my product key was. What are my options? Is there somewhere in the files on the old computer I can look it up? Can I receive a new key?
On the very same page you posted your question is a pinned topic that reads:
Computer Crashed? Lost Original Install File? Here is Your Solution. :) (http://knucklecracker.com/forums/index.php?topic=4976.0)
Try reading the instructions in that, since even though your computer hasn't crashed, you still have lost the product key.