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.exe application error 0xc0000000 freezes/disables FF

  • 1 reply
  • 2 have this problem
  • 1 view
  • Last reply by FredMcD

more options

Long time FF user. WIN7 64 bit PC. I have expunged and reinstalled Firefox 32 bit, 64 bit and Quantum each ..multiple times = Same error. AV deactivated and Added exceptions = Same error. Chrome, IE .. etc .. browsers function flawlessly. I use FF Quantum and same AV at my office with zero issues. I've compared settings between office and home.. no difference. FF will (finally) open after multiple clicks. Tried: Refresh, Add-ons disabled, Profile change and Safe Mode = Same error.

Long time FF user. WIN7 64 bit PC. I have expunged and reinstalled Firefox 32 bit, 64 bit and Quantum each ..multiple times = Same error. AV deactivated and Added exceptions = Same error. Chrome, IE .. etc .. browsers function flawlessly. I use FF Quantum and same AV at my office with zero issues. I've compared settings between office and home.. no difference. FF will (finally) open after multiple clicks. Tried: Refresh, Add-ons disabled, Profile change and Safe Mode = Same error.

All Replies (1)

more options

Let’s do a full clean re-install;

Download Firefox For All languages And Systems {web link}

Save the file. Then Close Firefox.

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

Windows: C:\Program Files C:\Program Files (x86)

Mac: Open the "Applications" folder. https://support.mozilla.org/en-US/kb/how-download-and-install-firefox-mac

Linux: Check your user manual. If you installed Firefox with the distro-based package manager, you should use the same way to uninstall it. See Install Firefox on Linux; https://support.mozilla.org/en-US/kb/install-firefox-linux

If you downloaded and installed the binary package from the Firefox download page, simply remove the folder Firefox in your home directory. http://www.mozilla.org/firefox#desktop ++++++++++++++++++++++++++++ Do Not remove the profiles folder.

Look for, and rename any Mozilla or Firefox program folders by adding .old to them. Do not rename the Mozilla Thunderbird folder if there is one.

After rebooting the computer, run a registry scanner if you have one. Then run the installer. If all goes well, remove the OLD folders when you are done. +++++++++++++++++++++++++++ If there is a problem, start your Computer in safe mode and try again.

http://encyclopedia2.thefreedictionary.com/Linux+Safe+Mode This shows how to Start all Computers in Safe Mode; Free Online Encyclopedia