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FIrefox no longer working after latest Windows 10 update

  • 3 replies
  • 1 has this problem
  • 21 views
  • Last reply by cor-el

SnappyHapper
SnappyHapper
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Last night, my Windows 10 laptop (annoyingly) ran an update and restarted my system while I was uploading some photos onto a website. I have been using Firefox with (relatively) few problems. However, on logging back in after this update in Windows 10 (30th Sept 2015), Firefox has refused to open up, telling me that it 'Couldn't Load XPCOM'.

Having looked at similar problems on this site, I have manually uninstalled all Mozilla files, and reinstalled with the latest version twice, but I still get this 'couldn't load XPCOM' message when I try to start Firefox.

This leaves me with the only option of Microsoft Edge as a browser. Have mercy and help me fix this soon!!!

Last night, my Windows 10 laptop (annoyingly) ran an update and restarted my system while I was uploading some photos onto a website. I have been using Firefox with (relatively) few problems. However, on logging back in after this update in Windows 10 (30th Sept 2015), Firefox has refused to open up, telling me that it 'Couldn't Load XPCOM'. Having looked at similar problems on this site, I have manually uninstalled all Mozilla files, and reinstalled with the latest version twice, but I still get this 'couldn't load XPCOM' message when I try to start Firefox. This leaves me with the only option of Microsoft Edge as a browser. Have mercy and help me fix this soon!!!

All Replies (3)

jscher2000 - Support Volunteer
jscher2000 - Support Volunteer
  • Top 25 Contributor
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I think it indicates that the updater/installer glitched and one or more files in your program folder are missing or corrupted. For that, I suggest:

Clean Reinstall

We use this name, but it's not about removing your settings, it's about making sure the program files are clean (no inconsistent, corrupted, or alien code files). As described below, this process does not disturb your existing settings. Do NOT uninstall Firefox, that's not needed.

(A) Download a fresh installer for Firefox 41.0.1 from https://www.mozilla.org/firefox/all/ to a convenient location. (Scroll down to your preferred language.)

(B) Exit out of Firefox (if applicable).

(C) Rename the current program folder, either:

(64-bit Windows folder names) 

C:\Program Files (x86)\Mozilla Firefox

to 

C:\Program Files (x86)\OldFirefox

(32-bit Windows folder names) 

C:\Program Files\Mozilla Firefox

to 

C:\Program Files\OldFirefox

(D) Run the installer you downloaded in (A). It should automatically connect to your existing settings.

Will Firefox start?

Note: Some plugins may exist only in that OldFirefox folder. If something essential is missing, look in these folders:

  • \OldFirefox\Plugins
  • \OldFirefox\browser\plugins
jscher2000 - Support Volunteer
jscher2000 - Support Volunteer
  • Top 25 Contributor
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By the way, have you shut down and restarted Windows since this problem began? Occasionally after updates Windows seems to start with privilege issues where it only has partial access to your user account. Restarting Windows has fixed otherwise inexplicable problems in several threads.

cor-el
cor-el
  • Moderator
  • Top 10 Contributor
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What security software do you have?

This usually happens because of a failed Firefox update that left you with a mixture of old and updated files in the Firefox program folder. This can happen if your security software keeps a handle on files in the Firefox program folder.