I am frequently asked how people can cost effectively scan and analyze security setups on their servers. Nessus is one way to go for sure, but others are available including the Center for Internet Security scanning tools at http://www.cisecurity.org/. The scanner currently does not scan XP SP2 or W2K3 Server but does Windows 2000. The tool should be updated shortly to bring the most current Microsoft OS's into view.

-brett hill