Retrieving a Lost QuickTime Pro Key for Electronically Purchased Software

I bought QuickTime Pro and it was delivered to me electronically. I don't remember my key, and I bought a new hard drive and did some other stuff to upgrade my PC, ultimately causing me to lose the setup and program installation files. How can I retrieve my key? I followed the article that said to go to your account and look at your order history, and I can see that my product was purchased but I do not see a key anywhere. If someone wouldn't mind helping me find my lost key, I will love you now and forever.