Microsoft Baseline Security Analyzer
As part of Microsoft's Strategic Technology Protection Program, and in response to direct customer need for a streamlined method of identifying common security misconfigurations, Microsoft has developed the Microsoft Baseline Security Analyzer (MBSA).

MBSA Version 1.1.1 includes a graphical and command line interface that can perform local or remote scans of Windows systems. MBSA runs on Windows 2000, Windows XP, and Windows Server 2003 systems and will scan for common system misconfigurations in the following products: Windows NT 4.0, Windows 2000, Windows XP, Windows Server 2003, Internet Information Server (IIS) 4.0 and 5.0, SQL Server 7.0 and 2000, Internet Explorer (IE) 5.01 and later, and Office 2000 and 2002. MBSA will also scan for missing security updates for the following products: Windows NT 4.0, Windows 2000, Windows XP, Windows Server 2003, IIS 4.0 and 5.0, SQL Server 7.0 and 2000, IE 5.01 and later, Exchange 5.5 and 2000, and Windows Media Player 6.4 and later.

http://www.microsoft.com/technet/treeview/default.asp?url=/technet/security/tools/Tools/mbsahome.asp