Microsoft's final version of the Windows Defender anti-spyware software is currently available for download at Microsoft's web-site.
Windows Defender is a free program that helps protect your computer against pop-ups, slow performance, and security threats caused by spyware and other unwanted software. It features Real-Time Protection, a monitoring system that recommends actions against spyware when it's detected and minimizes interruptions and helps you stay productive. Now with 2 free support incidents for Windows XP and Windows Server 2003.
Windows Defender can be downloaded at http://www.microsoft.com/athome/security/spyware/software/default.mspx