Norton is good but very intrusive, it also appears to be very dependant on the installation routine running absolutely spot on. If it doesn't then it causes problems, as illustrated by the number of postings it generates in this forum. I would suggest that you uninstall it click here then reinstall, making sure you deactivate all other running software as it says in the instructions ( I know nobody ever usually bothers, but in this case it's worth trying ).
If that doesn't work remove it and deposit in nearest bin, replacing with avast! Anti Virus click here and Kerio Firewall click here or if you want a combined AV/Firewall EZarmor click here