Mozilla Firefox is one of the popular browsers among the web developers. It ranks next to the Google Chrome among the internet users. As it has various extensions, it is used by advanced web developers. Mozilla has various updates, and it releases new updates to improve the older version of the technological platform. Some of the updates have various new features which will be helpful, but some updates may be an incompatible one in Windows. This may be due to several installed programs in Mozilla and due to some new features which do not support in Windows. One of the errors which faced while launching Mozilla in Windows is the error message saying “Couldn’t Load XPCOM.”
This error cannot be solved by rebooting your system. You may find some answers for restore the Mozilla Firefox. But it may not completely resolve the problems in the browser. There are some solutions to get rid off from this error. I’ll share the methods in this article to Fix Couldn’t Load XPCOM error.
Table of Contents
Methods to Fix “Couldn’t Load XPCOM” Error in Mozilla Firefox:
Uninstall and Reinstall Firefox
To come of out from the above problem then you have to completely Uninstall the Firefox and have to reinstall the newest version of Mozilla. You have to completely uninstall all the Firefox related files from your computer.
- First Uninstall Firefox from your computer.
- Then Remove Registry entries.
- Next, remove Mozilla from program filesDeleting it from Program Data Folder.
- Deleting it from Program Data Folder.
- And finally, deleting it from the App Data Folder.
This will completely uninstall the Firefox from your system. In this process deleting the files from the Registry entries will be a tedious step and some wrong handling will lead to some other errors in your system.To avoid this, you can download the Iobit Uninstaller to uninstall all the files related to the Firefox.

After uninstalling the Firefox, you have to perform one more action that is you have to delete a folder from the App data. To do that, open the Run Dialog box and type %appdata% and press OK.This will tend to open the Roaming folder and in that find the Mozilla and delete it.
Yeah, your Firefox is getting completely Uninstalled. Now download the newest version of Mozilla Firefox and use it.
Repair the Corrupted files
If you have downloaded any corrupted files from the Mozilla Firefox, then you may face this error. If this is the cause for the error in your system, then download and run Reimage Plus and scan the system. It will restore all the corrupted files and missing files. After finishing the scanning process, check out your Mozilla, now it will not show the error message “Couldn’t Load XPCOM.”

Start Firefox in Safe Mode
To start Firefox in Safe Mode, follow the below steps:
- The first step is Hold the Shift key and then double-click the Mozilla Firefox to open.
Then choose the option Start in Safe Mode - Firefox extension may be the reason behind this error message “Couldn’t load XPCOM.”
- At this case disable the installed Add-ons one by one until finding out which plugin causes the problem
- To disable the plugin from the main menu, first Choose Add-ons from the settings of Mozilla
- In the Extension Panel, there will be Disable option which helps to disable the Add-ons one by one
- Restart the Firefox normally until you find which extension creates the error message.
- Restore your Computer
If the above error message arises most often, then restore your computer to a previous working state. This can resolve the XPCOM error message.
Reset Firefox to Default
Follow the below-given steps to reset the Firefox Setting to Default:
- First Start Firefox in the Safe Mode
- In that choose the Refresh option
- Next again click on the Refresh Firefox option
This Refresh option restores all your browser settings to Default; it creates a new user profile, deletes all the Add-ons and removes the plugins, added search engines, etc.
But by refreshing the Firefox you cannot remove the Bookmarks, Cookies, Passwords, Browsing History, Personal Dictionary, and Web form auto-fill information.
Upgrade and Reinstall
It is one of the clearest ways to fix the error message “Couldn’t load XPCOM.” For this first, uninstall the Mozilla Firefox and reinstall a latest upgraded version of Mozilla Firefox from the other web browser like Chrome or Internet Explorer. Now you will not face the above error message.
Final Words
The above methods will give you an error-free Mozilla Firefox for your usage. Just scanning the system or rebooting the system will not rectify the error in Mozilla. I am sure anyone of the above methods will give you the way to get out of the error message. If you have any clarifications can send the comments.
Also see: Fix “Unfortunately Google Search Has Stopped Working” Error