Pre-installed versions of Norton usually only qualify for free updates for 3-months or 6-months from the date it was first installed, after which you have to pay an annual subscription fee to continue getting updates.
If that applies to you and you haven't already paid a subscription, I would take this opportunity to get an alternative package and remove Norton. It is notorious for being heavy on system resources and gives users more problems of various kinds than the competition.
If you decide to go that route you'll find plenty of recommendations from forum members. My own recommendation is the one I use myself:
ZoneAlarm Internet Security Suite:http://www.zonelabs....a...=GB&lang=en
If you don't mind having a separate firewall and antivirus from two different companies. I can also recommend these two which I also use together on my laptop:
ZoneAlarm Free (firewall):http://www.zonelabs....a...=GB&lang=en
Avast Home Edition (antivirus):http://www.avast.com...ast_4_home.html