I just got a notice that there were updates available for my Windows 2000 system (I get these whenever security updates are issued). I clicked on it and it told me that a new tool will be downloaded to do a one-time sweep of my system for common viruses (Sasser, MyDoom) and eliminate them. This tool will be issued monthly by Microsoft and will also be available from their website to download and manually run. Not bad! Though there is a sensible disclaimer that this tool should not be used in place of traditional antivirus software.