Ad-Aware 6 Plus

Electronic Punk of NTFS.org has put up a superb review of this fine piece of software. See below for linkage.

Ad-aware is THE award winning, multi-trackware detection and removal utility (designed for Windows 98 / 98SE / ME / NT40 / 2000 / XP Home / XP Pro) that will comprehensively scan your memory, registry, hard, removable and optical drives for known Datamining, aggressive advertising, Parasites, Scumware, Keyloggers, selected traditional Trojans, Dialers, Malware, Browser hijackers, and tracking components.

List of features:

Leading anti data-mining utility, features the best maintained and updated target base
Targets hundreds of systems and thousands of variations
All new, vastly improved, in-depth scanning engine
Includes an Advanced process browser full supporting installed extensions, linked to the in-depth scan engine
Fully customizable automated scanning modes
Webupdate module now fully integrated into the Ad-aware interface
Entirely new, highly improved user interface
All new plug-in concept allows for powerful expandability and updating without the need to download a new core-application
Automatic quarantine (backup) function capability
Enhanced logging capabilities
Powerful tweaking options allows tweaking all aspects of Ad-aware
Extended in-depth registry scans
Exporting and printing of HTML reports
Powerful command line options, to load config scripts and reference files from, and send logfiles to remote drives
Blocks Browser hijacker attempts, Active-X installations, IE save attempts, and unauthorized auto start entries
Includes a Popup stopper with customizable black-list
Smart process-blocking, including filter lists
Enhanced menus providing many more options.
Plus many other enhancements!