There's a virus message floating around lately with the subject of Microsoft Security Update, or something similar. It sends an attached file for you to click on and "update" your system. This is a virus-infected file. DO NOT click on it. Microsoft doesn't send out messages to the general public like this. You either have to join a techie-type mailing list or check their web site for update information. Remember to keep your virus definitions updated, and you should be fairly safe.