Want to Retrieve Norton Key!!!!

Hi;

I have 2 copies of Norton AntiVirus 2009. One of them is already installed on my PC the other is still not used. I formatted my PC today and I subscribed with the Key of the unused copy of Norton by mistake, and when I noticed that; I re-subsribed with the old one.

My question is: How to retrieve the key of the copy which I don't want to install? And stop the cuonting of the remaining days?

(Both copy are registerd in the same account)

thanx