Where is the Activation Key Stored After Installation?

I recently built a new computer, and, owning FSX gold and acceleration, hoped to play them on it. When I went to install however, I realized that I didn't have any of the packaging (AKA activation key) from when I bought them. I only have it installed on one computer, so I won't hit the limit, but I need to find the activation keys to register. I poked through the registry a bit, but haven't been able to find them.

Thanks!