Microsoft offers the free Microsoft Baseline Security Analyzer (MBSA) scan tool to easily assess the security state of Windows machines.

MBSA includes a graphical and command line interface that can perform local or remote scans of Microsoft Windows systems.

Microsoft Baseline Security Analyzer (MBSA) is an easy-to-use tool designed for the IT professional that helps small- and medium-sized businesses determine their security state in accordance with Microsoft security recommendations and offers specific remediation guidance. Improve your security management process by using MBSA to detect common security misconfigurations and missing security updates on your computer systems.

System Requirements:
· Supported Operating Systems: Windows 2000; Windows 7; Windows Server 2003; Windows Server 2008; Windows Server 2008 R2; · Windows Vista; Windows XP; Windows XP Embedded
· Windows Server 2008 R2
· Windows 7
· Windows Server 2008
· Windows Vista
· Windows Server 2003
· Windows XP
· Windows 2000

New features in MBSA 2.1
· Support for Windows Vista and Windows Server 2008
· Updated graphical user interface
· Full support for 64-bit platforms and vulnerability assessment (VA) checks against 64-bit platforms and components
· Improved support for Windows XP Embedded platform
· Improved support for SQL Server 2005 vulnerability assessment (VA) checks
· Automatic Microsoft Update registration and agent update (if selected) using the graphical interface or from the command-line tool using the /ia feature
· New feature to output completed scan reports to a user-selected directory path or network share (command-line /rd feature)
· Windows Server Update Services 2.0 and 3.0 compatibility

Download: Microsoft Baseline Security Analyzer 2.2.2170.0 32-bit (1.6 MB) | 64-bit (1.7 MB) | Screenshot | Homepage