You mean the windows loading circle on the desktop? Have you opened task manager to see if''' firefox.exe '''is actually running? Then end it and try again.

What's your computer system and Firefox version? Did you get the installer from; '''[http://www.mozilla.org/en-US/firefox/all/ Download Firefox For All languages And Systems]''' {web link}

It is possible that your firewall or other security software blocks or restricts Firefox without informing you, possibly after detecting changes (update) to the Firefox application. Remove all rules for Firefox from the permissions list in the firewall and let your firewall ask again for permission to get full, unrestricted, access for Firefox and the plugin-container process and the updater process. See: *https://support.mozilla.org/en-US/kb/server-not-found-connection-problem *https://support.mozilla.org/en-US/kb/Firewalls *https://support.mozilla.org/en-US/kb/fix-problems-connecting-websites-after-updating ---- Try to start Firefox in <u>Safe Mode</u> to see if that works. *Windows: hold down the Shift key while starting Firefox *Mac: hold down the Options key while starting Firefox *https://support.mozilla.org/en-US/kb/troubleshoot-firefox-issues-using-safe-mode