Firefox is "unable to connect" to any site, while other broswers can

Question

I've tried clearing my cookies and history, disabling addons/extensions and the firewall, changing/disabling proxy settings, and read several of the articles, but nothing seems to work. I was out of town for 2 days and everything was working fine when I left. Got back today and just kept getting "unable to connect" message for any website I tried to open. I tried to download chrome and opera, but the download had an error and just didn't work (chrome) and just stayed at 0% with nothing happening (opera). i'm able to get emails and get on websites via internet explorer.

Answer 1

Hello vtand06, did you also try a ''Clean reinstall'' ? This means you remove Firefox program files and then reinstall Firefox. Please follow these steps:
'''Note:''' You might want to print these steps or view them in another browser.
#Download the latest Desktop version of Firefox from [https://www.mozilla.org mozilla.org] (or choose the download for your operating system and language from [https://www.mozilla.org/firefox/all/ this page]) and save the setup file to your computer.
#After the download finishes, close all Firefox windows (or open the Firefox menu [[Image:New Fx Menu]] and click the close button [[Image:Close 29]]).
#Delete the Firefox installation folder, which is located in one of these locations, by default:
#*'''Windows:'''
#**C:\Program Files\Mozilla Firefox
#**C:\Program Files (x86)\Mozilla Firefox
#*'''Mac:''' Delete Firefox from the Applications folder.
#*'''Linux:''' If you installed Firefox with the distro-based package manager, you should use the same way to uninstall it - see [[Installing Firefox on Linux]]. If you downloaded and installed the binary package from the [http://www.mozilla.org/firefox#desktop Firefox download page], simply remove the folder ''firefox'' in your home directory.
#Now, go ahead and reinstall Firefox:
##Double-click the downloaded installation file and go through the steps of the installation wizard.
##Once the wizard is finished, choose to directly open Firefox after clicking the Finish button.
More information about reinstalling Firefox can be found [[Troubleshoot and diagnose Firefox problems#w_5-reinstall-firefox|here]].
<b>WARNING:</b> Do not use a third party uninstaller as part of this process. Doing so could permanently delete your [[Profiles|Firefox profile]] data, including but not limited to, extensions, cache, cookies, bookmarks, personal settings and saved passwords. <u>These cannot be easily recovered unless they have been backed up to an external device!</u> See [[Back up and restore information in Firefox profiles]]. <!-- Starting in Firefox 31, the Firefox uninstaller no longer lets you remove user profile data.Ref: Bug 432017 and https://support.mozilla.org/kb/uninstall-firefox-from-your-computer/discuss/5279 [Fx31] Windows uninstaller will no longer offer the option to remove personal data -->
Please report back to say if this helped you!
Thank you.