Previously, I used NAV and a trial installation of NOD32, both with Windows Firewall. Daily Ad-Aware SE and Spybot S&D scans always found trackers and spyware. A few days ago I installed PC-cillin IS2005, using the IS2005 Firewall in place of the Windows Firewall. While AD-Aware SE is still finding adware trackers, all scans by Spybot S&D have found no spyware at all. It's only been a few days, but it appears that PC-cillin IS2005 is at least somewhat effective in blocking spyware.