Firefox won't work after update (Windows 8)

I run Windows 8.  I did the update for Firefox and it will not connect to the internet.  In an attempt not to be a luddite, I did my due diligence and searched all over everywhere including the support/community.  I managed to "reset" the firewall as recommended somewhere (I'll never find that again), but this did not solve my problem, although now I get a 'cannot connect to server" message in Firefox instead of a blank tab, so I guess that counts as progress.  I also managed to find the "allow access" list for the Windows firewall (which is turned off b/c of Norton Internet Security), but the Norton interface will not allow me to do so/the option is not available or discoverable.  I've been at this now for several days.  

 

In an additional Kafkaesque wrinkle, at some point I must've set Firefox as my default browse,r so when I click on "Help" in the Norton home box, it will only open in Firefox, which is not working.  So, after poking around for a year,  managed to change my default browser to Opera.  After that,  Norton Internet Security would not open when I clicked on it in my start menu.  At that point I threw my computer in the lake and became a hermit.