Secunia PSI

Product: Secunia PSI v1.5.0.1
Company: Secunia ApS
Website: http://secunia.com
Type: Free
Requirements: Windows XP/Vista/7

The Secunia PSI is the FREE security tool that is designed with the sole purpose of helping you secure your computer from software vulnerabilities. Software vulnerabilities affect all applications installed on your computer, from the Operating System down to your email client, office application, instant messaging, and so on. 

Secunia is the world-leading provider of vulnerability intelligence. Secunia collects, evaluates, verifies, and analyses security information from public mailing lists, security and vendor websites, coordinated vulnerability reports, and internal research.

To help you secure your computer from software vulnerabilities, Secunia PSI will scan your computer for installed software and determine if any applications lack security updates.