How many computers?

I have Norton Internet Security 2012 installed on my desktop Pc and have just bought a laptop. I was under the impression that I could use my laptop with the same Norton account, in fact up to 3 computers, but checking the info page in My Norton Account it says licensed installs 1 available installs none. I don't really want to shelling out twice for another norton product so does this mean I cant use NIS on my new laptop?