Microsoft Baseline Security Analyzer (MBSA) is an easy-to-use, small and free tool that helps you to determine computer / network security state in accordance with Microsoft security recommendations and offers specific remediation guidance.
Thus you can improve your security management process by using MBSA to detect common security misconfigurations and missing security updates on your computer systems.
This tool is very recommended for home users, small- and medium-sized businesses organisations.
You can download and read more about Microsoft Baseline Security Analyzer on Microsoft.com