Iuse ZenOK Free Antivirus, and Zone Alarm for a firewall. Both are free for home users, and are regularly updated and great protection against viruses. Norton is just so much bloatware in my opinion. Back in the day, dos days to be exact, I held Peter Norton in almost god-like status.
As I already mentioned, I recommend to use free anti-malware tools like adwcleaner and malwarebytes.
Both are advise by bleeping computer and other top computer forums.
Both work well together with your antivirus and can help with things like - navegaki -(http://pcspywareshield.com/guides/navegaki-com/) as navigaki is not a virus and your antivirus is not supposed to detect it.