Personally, I have used zone alarm for a very long time, then while surfing around and checking different ports on various sites to make sure its working well, one stated that port 135 was posting as open and was a possible security threat. I then found Agnitum outpost firewall on the same site, downloaded it and wow!!!! Not only did it completly close port 135 that za had open, but further configuration also blocked ad's, and was able to better observe network traffic on my simple dialup. I would strongly choose outpost over za for a free firewall.