Recently my internet won't connect. The diagnostic tool comes up with the
following - the problem is probably a firewall, check HTTP port (80) HTTPS
port (443) FTP port (21). I can't find these ports. My ISP says there is
nothing wrong their end so it must be the computer. I have a Norton
(Symantec) firewall which is switched off and a windows firewall which is
switched off. Any ideas please?