Hey Photoworx, Sorry that you're dealing with such a weird issue. Did you have Firefox previously installed prior to grabbing version 64.0? I'm not sure what the issue is just yet but I have a friend who ran into almost exactly the same issue. He couldn't get the latest Firefox to run & display itself while on Win 10. We didn't solve it quite yet b/c he's very busy. But maybe you & I can get to the bottom of this? :)

My first idea is to setup you up with a few older Firefox builds of various flavors to see if any one of them starts up successfully. And then when we pin it down to which version is not working, we could file a bug with our developers for deeper investigation into what's causing this.

Previous Firefox versions (please uninstall after testing each one & before installing the next one): Firefox 63 64-bit: https://download.mozilla.org/?product=firefox-63.0.3&os=win64&lang=en-US Firefox 63 32-bit: https://download.mozilla.org/?product=firefox-63.0.3&os=win&lang=en-US Firefox 62 64-bit: https://download.mozilla.org/?product=firefox-62.0.3&os=win64&lang=en-US Firefox 62 32-bit: https://download.mozilla.org/?product=firefox-62.0.3&os=win&lang=en-US Firefox 61 64-bit: https://download.mozilla.org/?product=firefox-61.0.2&os=win64&lang=en-US Firefox 61 32-bit: https://download.mozilla.org/?product=firefox-61.0.2&os=win32&lang=en-US

Thanks, Noah. This is a first-time installation on my mother's new HP notebook. It's also my first experience with a "clean" Windows 10 installation. (Can you say "bloatware" boys and girls?)

Trying again with an older version makes sense, but as the notebook is now in another time zone, it will take some time before I can make that happen.

Blocking Firefox's access to the internet is one thing, but I'm at a loss to explain why entering "about: preferences" and "about:config" don't work. Is Firefox handing off everything to some system-level routine for parsing?

It is possible that security software (anti-virus, firewall) is causing the problem. Try to disable security software temporarily to see if that makes a difference.

It is possible that your firewall or other security software blocks or restricts Firefox without informing you, possibly after detecting changes (update) to the Firefox application. Remove all rules for Firefox from the permissions list in the firewall and let your firewall ask again for permission to get full, unrestricted, access for Firefox and the plugin-container process and the updater process. See:

• https://support.mozilla.org/en-US/kb/server-not-found-connection-problem
• https://support.mozilla.org/en-US/kb/Firewalls
• https://support.mozilla.org/en-US/kb/fix-problems-connecting-websites-after-updating

Do a clean reinstall of the current Firefox release and delete the Firefox program folder before installing a fresh copy of the current Firefox release.

• download the Firefox installer and save the file to the desktop
  *https://www.mozilla.org/en-US/firefox/all/

If possible uninstall your current Firefox version to cleanup the Windows Registry and settings in security software.

• do NOT remove "personal data" when you uninstall the current Firefox version, because this will remove all profile folders and you lose personal data like bookmarks and passwords including data in profiles created by other Firefox versions

Remove the Firefox program folder before installing that newly downloaded copy of the Firefox installer.

• (64-bit Firefox) "C:\Program Files\Mozilla Firefox\"
• (32-bit Firefox) "C:\Program Files (x86)\Mozilla Firefox\"

• it is important to delete the Firefox program folder to remove all the files and make sure there are no problems with files that were leftover after uninstalling
• http://kb.mozillazine.org/Uninstalling_Firefox

Your personal data like bookmarks is stored in the Firefox profile folder, so you won't lose personal data when you reinstall or update Firefox, but make sure NOT to remove personal data when you uninstall Firefox as that will remove all Firefox profile folders and you lose your personal data.

If you keep having problems then you can create a new profile to test if your current profile is causing the problem.

• https://support.mozilla.org/en-US/kb/Profiles
• https://support.mozilla.org/en-US/kb/back-and-restore-information-firefox-profiles

Reinstall Firefox

• https://support.mozilla.org/en-US/kb/troubleshoot-and-diagnose-firefox-problems

Thank you, cor-el.

Following a document I found here, I had already deleted the firewall entry for Firefox and recreated it. (I did it manually, per the instructions, rather than letting the firewall ask me about adding it.)

Deleting the personal data isn't an issue; this is the first install of Firefox on a new computer.

This is the piece that confuses me the most: Entering "about:preferences" in the address bar yields no results. The little "activity" dots go back and forth on the tab, but nothing happens. I don't think the firewall should be able to interfere with what is essentially an internal operation.

You can still try a clean reinstall in case something is wrong there.

Your personal data like bookmarks is stored in the Firefox profile folder, so you won't lose personal data when you reinstall or update Firefox, but make sure NOT to remove personal data when you uninstall Firefox as that will remove all Firefox profile folders and you lose your personal data.

• Help -> Troubleshooting Information -> Profile Directory:
  Windows: Show Folder; Linux: Open Directory; Mac: Show in Finder
• http://kb.mozillazine.org/Profile_folder_-_Firefox

Thanks, cor-el. I already tried a clean install. As noted before, there is no down side to deleting the personal data in this case because there IS no personal data. Firefox has yet to do anything. Since I couldn't get it to go to any websites, there isn't even any browsing history.

I think the next step is to completely remove it. Are there any utilities that will do a search and destroy to completely eliminate all traces of Firefox?

Dropping back to a much earlier version would provide a useful data point. If older versions work and the newest one does not, then that leads to one set of possibilities. But if an older version is similarly non-functional, it points to a different set of possibilities.

Photoworx said

Dropping back to a much earlier version would provide a useful data point. If older versions work and the newest one does not, then that leads to one set of possibilities. But if an older version is similarly non-functional, it points to a different set of possibilities.

Exactly. That's the conundrum my friend found himself in as well. We still haven't a chance to properly debug the issue. We guessed that maybe it could be a specific Windows 10 update that needs to be uninstalled. That was our educated guess since it seemed to be blocked from running at all on the OS level. So all signs point to Windows' fault in our opinion.

By you testing those versions, it would help greatly to see where the issue started exactly. And then I can dig deeper for a reference point of bugs or Windows Update patches that conflicted with that particular Firefox version. ;)