Avoid Comodo Firewall 6 for the time being, as this new version has a few bugs in it. Stick to the 5.x versions for now.
I experienced this when I finally did a factory restore to a laptop. v6 doesn't play nice with the AV I was using.
So I finally gave the Windows firewall another look. You can get windows 7 Firewall control if you like to be notified when a new program is asking for internet access.
I've the built in firewall against port scanners and it seems fine.
If you become familiar with wf.msc firewall configuration tool then it's pretty flexible as far as configuring firewall rules go.
http://www.t1shopper.com/tools/port-scan/
https://www.grc.com/x/ne.dll?rh1dkyd2
I've also tried checking it versus a couple of port scanners and it passed those tests.
So if you don't have enterprise needs and have a modern router that does it's own stateful packet inspection of incoming data between your computer and the modem, then the built in Firewall for windows is probably good enough, for the average use.
~edit~
I haven't yet tested the Windows Firewall on a public hotspot yet and I am wary of connecting to one regardless of the software firewall I am using.