Question: I am presently running windows firewall. Do I need another firewall? I have looked at these:
Which one would you recommend?
Answer: The worst firewall used to be the one built into Windows because in Windows XP it didn't protect you against anything that had managed to get onto your computer (perhaps by being attached to something that you intended to download). Once it was on your computer it could communicate out and could also update the firewall settings to allow itself to come back in after you find and delete it.
Any other firewall will stop such malware that has succeeded in getting in from being able to communicate out and also will not allow it to update the security settings so it wont be able to come back in automatically once you find and delete it. The Firewall in Windows 7+ also checks outgoing communication attempts and blocks those it considers may be suspicious. The potential weak point in the Windows 7 firewall is if malware manages to update the firewall settings as this is at least potentially a target depending on how popular simply using the built in firewall becomes.
Prior to originally answering this question I had purchased ZoneAlarm security suite for my computer which also has antivirus, antispyware, and web filtering (as well as a few other options I never looked at). I bought the upgrade of ZoneAlarm because I needed it to protect a network sharing internet access where the internet access was through one of the computers on the network. Now that I have the internet connected via a router where any of the computers can access the internet independently I have switched back to using free firewall software on each computer. Currently I am using the Comodo firewall on each individual computer on the network. The firewall built into the router is also enabled.
This article written by Stephen Chapman, Felgall Pty Ltd.