If you are using the computer for personal or at home, get rid of Norton. I personally use various softwares on my computers for security. Firewall is the free version of Zonealarm. Anti virus is covered by AVG, again free and it has a built-in email scanner. Since 1996, I have tried various Symantec products and always found them to be too aggresive for network and file activity monitoring. Keep it simple and try other products that are specialized for what you are trying to do. I never rely on an all-in-one package for internet security. There are more virii, trojans and spywares being produced every day. I monitor my firewall and anti virus on a regular basis to make sure I am not wide open to the net or prone to a virus I may have downloaded within some file.
Symantec is geared more towards business computing and therefore heavily armored. This requires more resources. That is my opinion.