Microsoft Windows Security Management

Microsoft's Baseline Security Analyzer (MBSA): The Free MBSA scans for missing security updates and common security misconfigurations. It offers an improved user experience, expanding product support and can be used in conjunction with Microsoft Update and Windows Server Update Services.
: Web Page Fix Software before it fails
This Service is so good; Microsoft now provides it as “Microsoft Update”. BigFix is useful for anyone with a computer running Microsoft Windows 95, 98, NT, 2000, Me, or XP that has Internet access. BigFix is a program that can intelligently detect and correct all kinds of problems on your computer, usually before they get a chance to mess up your computer. With BigFix, you are protected from known bugs, security holes, and problems caused by outdated software, letting you do more and crash less every day.
: Web Page See how your computer looks from a hacker's point of view.
Safety Center: Finds and fix safety and performance issues on your PC with Microsoft's Windows Live Safety Center free online scans.

Kill Popup v1.2

One Click ON/OFF Popup Killer
XP SP2 already has one!

Web Page SpywareBlaster doesn't scan and clean for spyware
it prevents it from ever being installed.

Microsoft's Malicious Software Removal Tool: The Free Microsoft Windows Malicious Software Removal Tool checks computers running Windows XP, Windows 2000, and Windows Server 2003 for infections by specific, prevalent malicious software–including Blaster, Sasser, and Mydoom–and helps remove any infection found.