Its Free : Ad-Aware 2008

From Lavasoft: With the ability to scan your RAM, Registry, hard drives, and external storage devices for known data-mining, advertising, and tracking components, Ad-Aware 2008 can clean your system easily, allowing you to maintain a higher degree of privacy while you surf the Web. Ad-Aware 2008 includes an improved threat detection, enhanced rootkit removal system, faster updates, Lavasoft ThreatWork to submit suspicious files for analysis, and is now compatible with 32-bit and 64-bit Windows Vista. Version 7.1.0.11 may include unspecified updates, enhancements, or bug fixes. Download : http://www.zdnetasia.com/downloads/pc/swinfo/0,39043052,39247373s,00.htm