For extra protection, install IE Spy-Ad. Its a simple Registry patch that adds thousands of malware sites to the Restricted Zone of Internet Explorer so they can't run any code that could install spyware or otherwise harm your computer. FREE to all users. https://netfiles.uiuc.edu/ehowes/www/main.htm
bump
with Ad-Aware Pro or Ad-Aware Plus you have real time protection which has worked extremely well for me. However, neither of these are free.
http://www.lavasoftusa.com/software/adaware/
That comes with the real-time AdWatch. Do you run it?
I recently bought the Pro version and installed AdWatch. However, I still seem to have gotten infected by the CoolWebSearch spyware. I had to restore my system from a backup.
-PJ