'''Reset Firefox...''' The Reset Firefox feature can fix many issues by restoring Firefox to its factory default state while saving your bookmarks, history, passwords, cookies, and other essential information. '''''Note:''' After resetting Firefox, you will lose any extensions, toolbar customizations, and some preferences.'' See the [[Reset Firefox – easily fix most problems]] article for more information. To Reset Firefox: # Open the Troubleshooting Information page using one of these methods: #*Click the menu button [[Image:New Fx Menu]], click help [[Image:Help-29]] and select ''Troubleshooting Information''. A new tab containing your troubleshooting information should open. #*If you're unable to access the Help menu, type '''about:support''' in your address bar to bring up the Troubleshooting Information page. #At the top right corner of the page, you should see a button that says "Reset Firefox" that looks like this: [[Image:Button reset]]. Click on it. #Firefox will close and reset. After it is done, Firefox will show a window with the information that is imported. #Click Finish and Firefox will reopen. '''If Resetting Firefox doesn't work...''' '''Certain Firefox problems can be solved by performing 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 -->

Hello npappous, try to boot the computer in [http://windows.microsoft.com/en-us/windows-8/windows-startup-settings-safe-mode Windows Safe Mode with network support] (also : http://support.microsoft.com/kb/2809468/en-us ) and then see if that helps. [select Enable Safe Mode with Networking] Most often issues like that are caused by a firewall or/and security software which doesn't recognize new Firefox (and for that blocks the new firefox version). You have to remove all program rules for firefox from your firewall and let it detect the new version of the browser again.{In windows safe mode with networking security software is disable} thank you