1:39 - Monday, 21 April 2014

Problems Launching Firefox: “Couldn’t Load XPCOM”

#Topics: could not load xpcom,couldnt load XPCOM,firefox could not load xpcom,COULDNT LOAD XPCOM FIREFOX,firefox couldnt load xpcom

I can’t open my Firefox. I don’t remember well how this problem came on, but apparently I’ve never made any changes to my computer or Firefox itself since the last time I could launch it successfully. I’m using Windows 7 Pro 64 Bits. Now, whenever I open Firefox, there is always an error message saying, “Couldn’t load XPCOM”. I haven’t reinstalled Firefox since I don’t wanna lose my important bookmarks. I hope you can help me resolve this problem.

Start Firefox in Safe Mode to check if one of the extensions (Firefox/Tools > Add-ons > Extensions) or if hardware acceleration is causing the problem (switch to the DEFAULT theme: Firefox/Tools > Add-ons > Appearance).

Do not click the Reset button on the Safe mode start window or otherwise make changes.
Mozilla Support
Mozilla Theme Support

You can re-install Firefox by just making a backup of your settings first. Do it via cloud sync (go to settings and click on sync) or backup the folder in your user directory.


Otherwise here is a thread on mozilla.

This message indicates failure to load xpcom.dll. Check the installation directory (most probably C:Program Files (x86)Mozilla Firefox) if it is there.