Today Microsoft released a public beta of its Anti-Spyware software.
Windows AntiSpyware (Beta) is a security technology that helps protect Windows users from spyware and other potentially unwanted software. Known spyware on your PC can be detected and removed. This helps reduce negative effects caused by spyware including slow PC performance, annoying pop-up ads, unwanted changes to Internet settings, and unauthorized use of your private information. Continuous protection improves Internet browsing safety by guarding over 50 ways spyware can enter your PC.
The worldwide SpyNet™ community plays a key role in determining which suspicious programs are classified as spyware. Microsoft researchers quickly develop methods to counteract these threats, which are automatically downloaded to your PC, so you stay up-to-date.
I just installed this program and it seems to detect some adware/spyware that isn't detected by Spybot S&D or Lavesoft's Ad-Aware. And it seems that this program also tries to detect trojans. Seems like a promising new program from Microsoft!
Microsoft's AntiSpyware Beta 1 program can be downloaded here