Security Analyzer is a simple tool that will quickly issue a report on your PC's security status.
Just launch the program and it will check to see if your system is being protected by a firewall, or an antivirus tool. It will also report on your Windows update status, and allow you to turn on User Account Control and Network Access Protection (if they're currently turned off).
And at the head of the report will be an overall rating for your system security, which if all is well should be highlighted by a reassuring green tick.
The program essentially works much like a slightly more powerful version of the Windows Action Centre, then, in both reporting possible configuration issues and allowing you to rectify them in a click or two.