I find it sort of interesting that Microsoft doesn't have its own virus protection and detection software product. They probably do not want to invest the money in setting up a virus research and removal tool production branches in such a heavily crowded market. But a virus scanner that was embedded in the operating system might provide a higher level of security, and it would be a logical extension to their built-in firewall. Do you know if Microsoft has ever publicly considered publishing their own antivirus software?