This site will have limited functionality while we undergo maintenance to improve your experience. If an article doesn't solve your issue and you want to ask a question, we have our support community waiting to help you at @FirefoxSupport on Twitter and/r/firefox on Reddit.

Search Support

Avoid support scams. We will never ask you to call or text a phone number or share personal information. Please report suspicious activity using the “Report Abuse” option.

Learn More

Firefox doesn't open at all (it works in windows safe mode, removed everything and reinstalled as well)

  • 6 replies
  • 2 have this problem
  • 63 views
  • Last reply by cor-el

more options

Dear support people,

I have an issue since 2 weeks that is driving me up the wall. I use Win 10 and have Norton installed

Firefox doesn't open, the loading circle spins for 5 seconds but nothing happens, it doesn't appear in taskmanager either.

I have: -Scanned my pc with norton and malwarebytes (clean) -unistalled Firefox and removed the folder containing the profile folder and then reinstalled.

The last action got it working again in windows safe mode but not in regular mode.

Is there anything I can check like a logfile to see what's preventing it from opening?

Note I am not posting this from the PC that has the issue, that pc is an old pentium 4 (I think a prescott) desktop. Besides firefox everything seems to work nicely, It is mostly used by my dad to play browser games.

Thanks for your time, Sven

Dear support people, I have an issue since 2 weeks that is driving me up the wall. I use Win 10 and have Norton installed Firefox doesn't open, the loading circle spins for 5 seconds but nothing happens, it doesn't appear in taskmanager either. I have: -Scanned my pc with norton and malwarebytes (clean) -unistalled Firefox and removed the folder containing the profile folder and then reinstalled. The last action got it working again in windows safe mode but not in regular mode. Is there anything I can check like a logfile to see what's preventing it from opening? Note I am not posting this from the PC that has the issue, that pc is an old pentium 4 (I think a prescott) desktop. Besides firefox everything seems to work nicely, It is mostly used by my dad to play browser games. Thanks for your time, Sven

All Replies (6)

more options

Hi, it may be that your security software - or some part of it, is causing this, so disable it to test.

Do other browsers/programs start normally? If so, try performing a Clean reinstall. This means you remove your Firefox program files and then reinstall Firefox. This process does not remove your Firefox profile data (such as bookmarks and passwords), since that information is stored in a different location.

To do a clean reinstall of 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.

Be sure to delete the Firefox installation folder as above.

Please report back to say if this helped you!

Thank you.

more options

Hi Scribe,

Thanks for the answer, other browsers work fine, in windows safe mode firefox works too.

I have tried to remove and re-install, but I'll do it again following your exact sequence, I removed it using the windows uninstal function and then deleted the folder.

I'll let you know the outcome.

more options

Please install the Extended Release Version if not already https://www.mozilla.org/en-US/firefox/organizations/all/ since we have no info on anything as to what you are running on the old Machine. You may want to dig through the registry also and delete all entries you can find. Note : You have possibly reached the limit of what that machine can do. It is possible to use Driver Max (or) and update Motherboard Drivers and Chipset but there are risks.

As for the machine you came in on says Running newest Firefox... That means nothing to us. Too many people think they are running newest release and are not. Newest is Firefox 56.0.2 https://www.mozilla.org/firefox/all/ Note Firefox 57 Quantum release date Nov 14th https://www.mozilla.org/en-US/firefox/quantum/ Note : all Legacy Extensions will be disabled or removed.

Note : Update your Flash as your running a security risk ver 26 Flash Player Version: 27.0.0.183 https://get.adobe.com/flashplayer/otherversions/ Step 1: Select Operating System Step 2: Select A Version (Firefox, Win IE . . . .) Note: Other software is offered in the download. <Windows Only>

Please let us know if this solved your issue or if need further assistance.

more options

Hi PkShadow,

I did what scribe said, didn't solve it, then I deleted everything again including the profile folder and the result is the same, it works in windows safe mode but not in regular mode.

I'll try to check the registry tonight and try the extended release.

I assumed I have the latest version since I downloaded the latest version from the site. I also assume the machine is not on his limit since firefox worked fine 2 weeks ago and has no problems running chrome/edge/opera.

Thanks for your time and effort!

Regards, Sven

more options
more options

You can find the full version of the current Firefox release (56.0.2) in all languages and all operating systems here: