You can try a program called malwarebytes to clean it up. It is free and works good. You can get it from www.malwarebytes.org
I don't know. I've been on Nortons for a long time. I haven't had any problems with them yet. However I used to have a netbook with a different anti-virus. Unfortunately I got rid of it and the anti-virus program on it was a piece of shit. That's why the official computer of Grinkfest/ Arcade Outsiders uses Nortons.