I also hate Nortons. I stopped using it many years ago and switched to free products (AVG then Avast! more recently).
It is important to install critical updates from microsoft as soon as possible to protect against these sort fo vulnerabilities. The irony of the situation is that the worm you seem to have been affected by is a worm that attaches itself to the background service which downloads the windows updates, and it probably attached itself to the critical update microsoft released to address it
http://www.microsoft.com/technet/sec.../ms08-067.mspx