Where do I enter activation key?

Recently upgraded from Counterspy to Vipre, but delayed activating Vipre until I could remove Norton AV. Now that other AV is uninstalled, I tried to extend subscription, but apparently that is wrong action. Original product key is displayed and won't allow me to overwrite it with activation key for Vipre.
How do I enter my activation key? Thanks in advance.
A couple of hours later...I went back to an earlier topic and found the answer provided by Nick H. Open Vipre, in upper left, click help, then Register. Enter Activation key here. Careful reading is needed to ensure you can tell a number 1 from letter I, zero from letter O, number 5 from letter S...All is resolved now.