Where do I add new product key to add Norton to my pc?

Norton chat said to go to My Account, then to Renewal Option to add the product key but I can't find any place to do this. Can anyone tell me how to add this? I bought version 4.0 on a CD at the store when I purchased my son a laptop and now have 2 activations left and want to use them for my own laptop and desktop.

MyAccount.JPG

 

You can use 'Renew Subscription' under My Accounts window.