Comodo Firewall updated to 2.4.17.183

How easy is comodo to set up?

I installed a copy a few months ago and it completely knocked out my network/internet connection.
No, I'm not a noob at windows or pc's, I've almost completed my Diploma of Network Engineering
along with years of practice and fiddling at home.

I couldn't be bothered fiddling with the settings so I uninstalled and put back the previous one, I decided that any firewall that
disabled Internet altogether as soon as I completed installing, just wasn't worth the trouble as I wouldn't be recommending it to anyone.

Though seeing its getting recommended by people around the forum,
I was thinking about testing it out again...
What did I miss during install the last time?

Make a System Restore point first because it doesn't like to uninstall clean and will leave residue behind to the point where Windows Security Center will still think it's installed.