Re: Firefox won't open/connect tp the internet. Explorer opens and connects. Windows firewall turned off. No other antivirus program running. Happened when I downloaded new Firefox update.
I had the same problem when i dl-ed a new anti-virus softward, but what I did help me reconnect Firefox again!
Here is what I did,
Go to open firefox browser-->option-->advanced-->network-->settings-->and change it to auto-detect proxy settings for this network!
It worked for you, hope it will work for you too =)!