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None of the Websites I Try to Visit Load in Firefox.

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I was using Firefox as usual when Bitdefender, my antivirus app, apparently caught a Firefox-related file it thought was malicious and either quarantined or deleted it.

Now, Firefox will not display any websites at all. The other web browser on my computer Microsoft Edge, displays the websites just fine and is not having issues. But not Firefox.

I tried uninstalling and then reinstalling Firefox, to no avail. I also tried to restart my computer, again to no avail.

What do I need to do to have Firefox back up and running again?

I was using Firefox as usual when Bitdefender, my antivirus app, apparently caught a Firefox-related file it thought was malicious and either quarantined or deleted it. Now, Firefox will not display any websites at all. The other web browser on my computer Microsoft Edge, displays the websites just fine and is not having issues. But not Firefox. I tried uninstalling and then reinstalling Firefox, to no avail. I also tried to restart my computer, again to no avail. What do I need to do to have Firefox back up and running again?

All Replies (1)

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Does Bitdefender have a log or history that shows what it did?

If it removed a file from the programs folder --

C:\Program Files\Mozilla Firefox

-- then re-running the installer to do an in-place update might resolve the issue. (If you want to try that, you can download from: https://www.mozilla.org/en-US/firefox/all/#product-desktop-release )

On the other hand, if it removed a data or settings file, hmm, it would be useful to know which one to suggest next steps.


One other thought. Firefox depends on a shared Microsoft file named VCRUNTIME140_1.DLL file. If that file is removed, Firefox doesn't work properly from the address bar down.

To rule out that issue, you can (re)run Microsoft's installer for the VC Runtime files:

(A) Open https://docs.microsoft.com/en-US/cpp/windows/latest-supported-vc-redist?view=msvc-160#visual-studio-2015-2017-2019-and-2022

(B) In the "Visual Studio 2015, 2017, 2019, and 2022" section of the article, download the installer for your system:

  • 64-bit Windows: the "X64" download
  • 32-bit Windows: the "X86" download

(C) Run that installer and restart Windows.

Any improvement?