<A target="_blank" href="http://www.infoworld.com/d/windows/microsoft-security-essentials-free-so-whats-the-catch-105?source=rss_infoworld_top_stories_">Microsoft Security Essentials (MSE) is Microsoft's newest anti-spyware tool</A> to replace Windows Defender. You can download it from Microsoft for free. This article explains the basics of MSE.