It says "Cannot connect to the Internet", and I know it's because of the firewall, but the problem is that I don't know what to tell this firewall to do. He doesn't allow NetBeans IDE to create a new Internet connection(which I find normal, 'cause I already have one and it should use the one I already have). I am not using proxy, so I selected no proxy in the Option/General/Proxy Configuration.
I really don't know what to do, especially because I can't really identify the process that is being blocked by the firewall.
If the default Windows Firewall is on, it will not be a problem. It provide enough safety against the such attacks. Actually it is the only way to solve your problem. Disabling that Norton Firewall and continue your works or enabling it and stay offline is up to you.
go to "Norton Personal Firewall" configure. In Advanced Settings, change the following one of the General Rules
Default Allow Outbound ICMP
to use All protocols, not just ICMP. The default of Norton use ICMP. good luck.