I am using Avast Internet Security and have a simple question. In my current set up, I am using the free COMODO firewall. Therefore, I disabled the Avast firewall and the Windows 7 firewall. My question involves software conflicts. Would I have a serious conflict problem if I enabled the Avast firewall while running the COMODO firewall? Typically, 2 or more firewalls should not be run simultaneously. Thanks for your help.
Hi,
first question: why did you acquire IS if you already knew that you’d keep using CIS firewall ? pro was enough may be 
to your question: DO NOT run two firewalls at the same time, especially Comodo + Avast together would be a disaster, conflicting about rules etc…you have to make a choice don’t use Avast FW just because you bought it, use it if you want to replace the one you used before.
With software firewalls on the same system, you really only need to use one, as they would end up fighting each other. Anytime you installed a new program that wanted internet access, you would have to do twice the work to open up the firewalls on your system. Pick the firewall you like the best and use that.
For me the debate is still out on disabling Windows firewall when using Avast IS. According to ( http://forum.avast.com/index.php?topic=53845.0 ) and VLK’s posts during the beta test, you should have both on.
yeah the argument for keeping Win FW on is that it’s doing non-firewall tasks as well, and the example given was IPSec http://en.wikipedia.org/wiki/IPsec . I personally turn it off. Might change my mind once I know what IPsec exactly is.