Symantec Client Firewall is blocking my Internet connection

Well, what you can try is to uninstall Norton and see if that REALLY is the problem. The other thing you can do is tweek the Norton out settings. Or maybe (if you have vista) your windows defender is on as well. I have Norton 360 and when my windows defender is on, Norton goes loopy. I don't know why, but I guess it's that they can't run at the same time because then they will like fight each other. Anyways, it's better to get full protection (like Norton 360) than just Norton Internet Security.

Anyways, hope this helps.

I would recommend disabling the Norton firewall portion of the software, keep it's antivirus side if you wish, and use Windows Firewall for best compatibility.