Trend Micro notified me of virus and did scan and sys update last week. Trend Micro has a free version at their website.
It seems more user friendly to me then Norton.
It is, IMHO, but Trend had a little hoo-hah last week when they released a signature file that locked their clients' machines solid. They corrected it right away, but it sort of hurt my sales program here at work to switch from Symantec.