I assume you have a Norton account and a current subscription. What you need to do is to download the Norton Removal Tool off the web to delete all traces of Norton off your computer. You can then follow the steps to reinstall Norton via your account. It won't cost you a penny and is easy and quick to do.
In my case, I foolishly tried to install an additional malware program off the web which interfered with Norton and prevented me from opening the main interface. The removal of Norton via the tool and subsequent re-installation solved the problem