Nimda worm is addressed on the norton site. There's a special cleaner patch and instruction that you can download. Keep your definitions up to date and look at their site from time to time. Also, you might find it useful to review from time to time the McAffee and Computer Associates site. I've found that no matter what virus engine you have, there is no one engine that does it all. One of the competitors may have a patch, or directions sooner than another. That's not to knock Norton AV. We use CA at work and I use Norton at home, and we use McCaffee on the laptops.