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Cannot download. Error message "download cannot be completed" because previous version still operating; have deleted prior versions from system; still no luck.

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  • Last reply by FredMcD

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Tried to install latest version of Firefox including upgrade [46.0 (x86 en-US) on my current system using Windows 10; Several weeks ago I was having a problem with Firefox browser and was advised to delete it along with the corresponding Mozilla maintenance system with it and "re-install" at a later date. When I finally got around to installing the upgraded version, the download was going smoothly until the following error message appeared: "Firefox is already running but is not responding. The old Firefox process must be closed to open a new window." I checked to ensure that all previous Firefox software had been deleted and tried to download again. Tried this several times with same resulting error message. How or Where do I find any previous versions of Firefox so that I can properly delete them and make sure the new version will complete its downloading successfully? Thanks very much for your assistance.

Tried to install latest version of Firefox including upgrade [46.0 (x86 en-US) on my current system using Windows 10; Several weeks ago I was having a problem with Firefox browser and was advised to delete it along with the corresponding Mozilla maintenance system with it and "re-install" at a later date. When I finally got around to installing the upgraded version, the download was going smoothly until the following error message appeared: "Firefox is already running but is not responding. The old Firefox process must be closed to open a new window." I checked to ensure that all previous Firefox software had been deleted and tried to download again. Tried this several times with same resulting error message. How or Where do I find any previous versions of Firefox so that I can properly delete them and make sure the new version will complete its downloading successfully? Thanks very much for your assistance.

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Let’s do a full clean re-install; Download Firefox 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.

Do Not remove the profiles folder.

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

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.

Starting The Computer In Safe Mode;
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