How to Fix – Couldn’t load XPCom – Error in Firefox

Do you experience the annoying “Couldn’t load XPCom” error in Firefox? If you see the Couldn’t load XPCOM error in Firefox, then you can’t start Firefox, or Firefox won’t start or load properly.

The Couldn’t load XPCom error in Firefox occurs if Windows has been restored to a backup or if there is malware on the computer. In this article, I will give you instructions on how to fix the Couldn’t load XPCom error in Firefox.

First of all, you need to uninstall the current Firefox installation. You will need to uninstall it via the control panel.

Click on the Windows start button, go to Settings on the left side. In the Windows, Settings click on Apps.

windows control panel

Sort the apps by name and search Firefox. Click on the Firefox installation and click on the Uninstall button.

firefox apps

Confirm the Firefox uninstall process by clicking Uninstall. You have now uninstalled Firefox, proceed to the next step.

Open a new Windows Explorer window. In the address bar type: %appdata%. Select the folder “Mozilla” and delete the Mozilla folder.

delete mozilla folder

In the same window type: %temp%, select all files with CTRL+A in the temp folder and delete the files.

Now go to and install the latest version of Firefox.

install firefox

You have now successfully fixed the Firefox “Couldn’t load XPCom” error.

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