Adware Remover: Ad-Adware se
Been using this one for years. At the bottom there is a link for the latest free version:

Ad-Aware 2007 Plus provides powerful protection that detects deceptive malware and spyware applications before they integrate into your PC and steal your personal information.
With an on-demand scanner and real-time monitoring, Ad-Aware protects you from dangerous intruders and prying eyes.

To download or for more info: Ad-Aware 2007 Free - Lavasoft