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After installing Sophos on my Windows 10 PC Firefox does not complete its startup and ceased to work

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  • 4 have this problem
  • 1259 views
  • Last reply by FredMcD

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Windows 10 and Firefox were running well on my (old) windows 10 Compaq pc. After uninstalling eset nod32 and installing Sophos it ceases to really start up. In task manager I see Firefox somewhere down below, but it does not complete the startup so I do not see the browser opening. Killing the Firefox instance, reinstalling and restarting it without any add-ons (they were https everywhere, bluehell firewall, CSfire, Click&clean , Privacy Badger) does not do the trick  :-(

Can you help (other than unistalling sophos...) ?

Cheers, Wim

Chosen solution

As a test, can you disable sophos? What does this do?

What is your computer system and Firefox?

Download Firefox Full Version 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.

• 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.


Look for, and rename any Mozilla or Firefox 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.

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Chosen Solution

As a test, can you disable sophos? What does this do?

What is your computer system and Firefox?

Download Firefox Full Version 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.

• 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.


Look for, and rename any Mozilla or Firefox 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.

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Hi Fred,

It was indeed only the Sophos software that made the difference in working or not. I have used revouninstaller to just get rid of all traces (both registry as welll as files and directories) to make a clean install of both Mozilla Firefox and Sophos. Without Sophos all is working well, with Sophos it does not. So I will have to look at another option to combat viruses and other threats.

Cheers, Wim

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Glad to help. There are many good programs out there.

Safe surfing.