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Firefox will not start anymore on Windows 10 Pro

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Within the last few days, Firefox is ceasing to work on our Windows 10 Pro machines. Possibly after receiving the latest update to 49.

Have uninstalled and re installed with fresh download. No help

Within the last few days, Firefox is ceasing to work on our Windows 10 Pro machines. Possibly after receiving the latest update to 49. Have uninstalled and re installed with fresh download. No help

All Replies (3)

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Many have been having problems with v49 and now v50.

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. If you downloaded and installed the binary package from the Firefox download page, simply remove the folder Firefox in your home directory.

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.

After rebooting the computer, run a registry scanner. 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.

Starting The Computer In Safe Mode;
Free Online Encyclopedia

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If you are still having problems, let us know. You can try reloading the last version that worked for you.

Look for the directory of the version that you want. Install an older version of Firefox {web link} But remember that old versions may have security issues.

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hi, mozilla just released an update to firefox 49.0.2 that should fix a problem that sound pretty similar to what you've described. you can download this new version from https://www.mozilla.org/en-US/firefox/all/ to see if it works for you too.