Norton Internet Security Subscription

Hello everyone, I came home from work today and was surprised to find that Norton Internet Security was turned off and asking me to subscribe in order to protect my computer. I still had a few months left on my subscription. I got it in October and well I can't find the product key.

When I bought this computer it came with a free Norton Internet Security trial so when I purchased the subscription I had gotten an e-mail with my product key in it but now I can't find the e-mail nor the paper I'd written down the key on. I'd rather not have to spend another 60$ yet. Anything I can do?

Thanks a lot. :]