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Firefox Still Not Working After Complete Uninstall And Reinstall

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I am using windows 7 and firefox has not been running properly.

1. Firefox will not open backup if I close it. I have to restart my computer to reopen it again. 2. No matter what I do I can't change firefox to be my default browser.

I have tried to fix both of theses problems by doing a complete uninstall where I get rid of all files related to firefox and then did a reinstall. The problems are still there. I need some help especially with making firefox my default browser

I am using windows 7 and firefox has not been running properly. 1. Firefox will not open backup if I close it. I have to restart my computer to reopen it again. 2. No matter what I do I can't change firefox to be my default browser. I have tried to fix both of theses problems by doing a complete uninstall where I get rid of all files related to firefox and then did a reinstall. The problems are still there. I need some help especially with making firefox my default browser

Modified by ebiz81

Chosen solution

Did you follow the below steps when removing Firefox?


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.

  1. Download the latest Desktop version of Firefox from mozilla.org (or choose the download for your operating system and language from this page) and save the setup file to your computer.
  2. After the download finishes, close all Firefox windows (or open the Firefox menu New Fx Menu and click the close button Close 29).
  3. 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 Install Firefox on Linux. If you downloaded and installed the binary package from the Firefox download page, simply remove the folder firefox in your home directory.
  4. Now, go ahead and reinstall Firefox:
    1. Double-click the downloaded installation file and go through the steps of the installation wizard.
    2. Once the wizard is finished, choose to directly open Firefox after clicking the Finish button.

More information about reinstalling Firefox can be found here.

WARNING: Do not use a third party uninstaller as part of this process. Doing so could permanently delete your Firefox profile data, including but not limited to, extensions, cache, cookies, bookmarks, personal settings and saved passwords. These cannot be easily recovered unless they have been backed up to an external device! See Back up and restore information in Firefox profiles.

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All Replies (8)

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Chosen Solution

Did you follow the below steps when removing Firefox?


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.

  1. Download the latest Desktop version of Firefox from mozilla.org (or choose the download for your operating system and language from this page) and save the setup file to your computer.
  2. After the download finishes, close all Firefox windows (or open the Firefox menu New Fx Menu and click the close button Close 29).
  3. 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 Install Firefox on Linux. If you downloaded and installed the binary package from the Firefox download page, simply remove the folder firefox in your home directory.
  4. Now, go ahead and reinstall Firefox:
    1. Double-click the downloaded installation file and go through the steps of the installation wizard.
    2. Once the wizard is finished, choose to directly open Firefox after clicking the Finish button.

More information about reinstalling Firefox can be found here.

WARNING: Do not use a third party uninstaller as part of this process. Doing so could permanently delete your Firefox profile data, including but not limited to, extensions, cache, cookies, bookmarks, personal settings and saved passwords. These cannot be easily recovered unless they have been backed up to an external device! See Back up and restore information in Firefox profiles.

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Yep, I did all that and then I just did it again. The same problems are there. After I reinstalled it and clicked on firefox icon nothing happened. It acted like it was going to start but nothing happened. Still having same issues.

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Could it be a virus causing firefox to act like this? Firefox works on my laptop

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Did you check in the Windows Task Manager to verify that Firefox closes properly?

Use "Firefox > Exit" (Windows: Firefox/File > Exit; Mac: Firefox > Quit Firefox; Linux: Firefox/File > Quit) to close Firefox if you are currently doing that by clicking the close X on the Firefox title bar.


You can check for issues caused by plugins and set all plugins to "Ask to Activate" on the "Firefox/Tools > Add-ons > Plugins" page (plugins are not affected by Firefox Safe Mode)

Start Firefox in Safe Mode to check if one of the extensions (Firefox/Tools > Add-ons > Extensions) or if hardware acceleration is causing the problem.

  • Switch to the DEFAULT theme: Firefox/Tools > Add-ons > Appearance
  • Do NOT click the Reset button on the Safe Mode start window

Create a new profile as a test to check if your current profile is causing the problem.

See "Creating a profile":

If the new profile works then you can transfer files from a previously used profile to the new profile, but be cautious not to copy corrupted files to avoid carrying over problems.

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If all else fails;

Download Firefox Full Installer For All languages And Systems {web link} Save the file. Then;

Using your file browser, open the Programs folder on your computer.

Windows: C:\Program Files C:\Program Files (x86) Mac: Open the "Applications" folder. Linux: Check your user manual.

Look for, and rename any Mozilla and Firefox folders by adding .old to them.

Now run the full installer. If all goes well, remove the OLD folders when you are done.

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Viruses and other infections are always a possibility on Windows systems. Here are so great free scanners to repair any issue with infection:

Microsoft Security Essentials is a good permanent antivirus for Windows 7/Vista/XP if you don't already have one.

Further information can be found in the Troubleshoot Firefox issues caused by malware article.

Did this fix your problems? Please report back to us!

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Thx for all the help, I got it working now. I did what Wesley Branton said.

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Glad to help. Thanks for contacting the Mozilla support team.