First thing is security

I prefer Norton because they are big and good leaders in problematic situation detection.
Plus I find Norton way cheaper than any other commercial security software here is why: Once you buy a norton antivirus software, you never have to buy an other version (until proven wrong)

So you are getting a warning that your antivirus is out of date? Then they refer to a norton page where you have to pay for membership renewal? Don't get caught in this publicity stunt. Norton has a page where you can go to manually update the virus definition.



To manually update your Norton virus definition takes about 1minute or less so there is no need to pay for subscriptions and new software.

If your virus detection software can detect all viruses, what else can you ask for?

First step:
On this page:  http://www.symantec.com/business/security_response/definitions/download/detail.jsp?gid=n95
You will find different executable files that will update the virus definition for different versions of Norton anti-virus software.

For example "if you run Norton 360 version 1.0 for Windows XP/Vista"
Click the second file in the list under Filename. The file name starts with the year and ends with i32.exe. e.g. 20070828-017-i32.exe

For more explanation on how to update virus definition files using the Intelligent Updater: Manual Steps visit the following link:
http://www.symantec.com/norton/support/kb/web_view.jsp?wv_type=public_web&docurl=20080407145621EN