Be advised, Norton is the worst anti-virus product ever made. Norton acts more like a virus and entrenches itself deep into your system. The software will do more harm to your PC than good and when you to to remove it, it leaves behind over 375 traces in your registry files/folders and subsystem. You have to download their removal tool just to get it off of your system. You are much better off with a free anti-virus product.
NOD32 and Kaspersky are the best anti-virus applications and much better than the best sellers Norton and McAfee (recent tests at av - comparatives.org). If you want a free anti-virus, AVG, Avast! or AntiVir all are better than Norton (install only 1).