"Couldn't load XPCOM" - tried everything

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GarethB
Posts: 118
Joined: May 7th, 2006, 9:11 am
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"Couldn't load XPCOM" - tried everything

Post by GarethB »

I have tried seemingly everything bar reinstalling Windows 10 to try to get Firefox to work again.

I've moved my profile to an external HDD, and deleted everywhere I know that Firefox is located:

C:\Program Files\Mozilla Firefox (OR)
C:\Program Files (x86)\Mozilla Firefox
C:\Users\*username*\AppData\Local\Mozilla\Firefox
C:\Users\*username*\AppData\Local\Mozilla\updates
C:\Users\*username*\AppData\Local\VirtualStore\Program Files\Mozilla Firefox
Plus even the 'roaming' ones, too

AND used the Advanced scan with Revo Uninstaller to remove every other trace of Firefox - registry included.

I've also tried another suggestion that has already been said on here before:
Close all applications and reboot the computer.
Delete any downloaded or partially downloaded installer files.
Clear the browser cache (of whatever browser you are using to download FF) and the Windows Temp directory.
Shutdown any anti-virus software you are running.
Download a new copy of the full installer from http://www.mozilla.org/en-US/firefox/all
Delete the directory C:\Program Files\Mozilla Firefox
Run the installer.
Restart the anti-virus program.
But after [the ridiculously long process of] reinstalling firefox, it worked ONCE [and once only], but after restarting Firefox, the same message appears again!
I've ran out of ideas (and running out of patience) as to why it still keeps saying this.

I don't know if it's just because my computer's so old or not, but seems to take at least something like 10 minutes to install it! And to keep on trying to uninstall it and reinstalling it all the time seems to take forever.

Any help will be much appreciated. I don't like the other webbrowsers, and for the time being I'm using the Mozilla-based program CLIQZ - but I can't install any addons to it, as it's a "privacy browser".
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dickvl
Posts: 54146
Joined: July 18th, 2005, 3:25 am

Re: "Couldn't load XPCOM" - tried everything

Post by dickvl »

Sounds that you have some (security) software that protects Firefox in such a way that it prevents Firefox from functioning properly.
You probably need to boot the computer in Windows Safe Mode with network support and do a clean reinstall (rename or remove the Firefox program folder) and reinstall the current release.
https://www.mozilla.org/en-US/firefox/all/

You can make a backup copy of the Firefox program folder to be able to see if and what files are missing or replaced by older copies after rebooting the computer.
This is possibly a problem with the XUL.dll file that stores the main Firefox code, but more files might be affected.

What security software do you have?
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