Unable to connect
Firefox can't establish a connection to the server at www.google.com
* The site could be temporarily unavailable or too busy. Try again in a few
* If you are unable to load any pages, check your computer's network
* If your computer or network is protected by a firewall or proxy, make sure
that Firefox is permitted to access the Web
Solution was to disable all extensions only, or this plus backup/remove cookies, etc. stored by Firefox, and reinstall.
How do I disable extensions?