This article describes how to uninstall an extension or theme that can't be removed by following the instructions in Disable or remove Add-ons or Remove a toolbar that has taken over your Firefox search or home page.

• If you are not able to uninstall a plugin, see Manually uninstalling a plugin.

Uninstall from Firefox Safe Mode

If you can't access the Add-ons Manager or if the Remove button is grayed out for a certain add-on, you may need to uninstall it from Firefox Safe Mode.

1. At the top of the Firefox window, click the Firefox button, go over to the Help menuOn the menu bar, click the Help menuAt the top of the Firefox window, click the Help menu and select Restart with Add-ons Disabled.... Firefox will start up with the Firefox Safe Mode dialog.

   Note: You can also start Firefox in Safe Mode by holding down the shift key while starting Firefox.holding down the option key while starting Firefox.quitting Firefox and then going to your Terminal and running: firefox -safe-mode
   You may need to specify the Firefox installation path (e.g. /usr/lib/firefox)
   Click the menu button , click help and select Restart with Add-ons Disabled.... Firefox will start up with the Firefox Safe Mode dialog.

   Note: You can also start Firefox in Safe Mode by holding down the shift key while starting Firefox.holding down the option key while starting Firefox.quitting Firefox and then going to your Terminal and running: firefox -safe-mode
   You may need to specify the Firefox installation path (e.g. /usr/lib/firefox)
2. In the Firefox Safe Mode dialog, click Continue in Safe ModeStart in Safe Mode.

Once Firefox has started in Safe Mode, try removing the add-on again and then restarting Firefox.

Extensions installed by other software

Sometimes installing or updating other software will add an extension which can't be removed from within the Firefox Add-ons manager because its Remove button is not functional.

The software that added the Firefox extension may include an option to remove it. You should visit the support site of the software provider for more information. As an alternative, simply disable the extension in the Firefox Add-ons manager if you no longer wish to use it. To disable the extension, select it, then click on its Disable button. The extension will be disabled after you restart Firefox.

Microsoft .NET Framework Assistant

If you have programs that use Microsoft .NET Framework components, a Microsoft update may have installed an extension called Microsoft .NET Framework Assistant.

To remove this extension, follow the instructions in Microsoft's article How to remove the .NET Framework Assistant for Firefox.

Java Quick Starter

If you have Java software installed, you may see the Java Quick Starter extension in your list of extensions. This extension has its Remove button disabled.

To remove this extension, follow the instructions to disable the Java Quick Starter in Oracle's Java Quick Starter article. You may need to close Firefox while executing those instructions.

When you restart Firefox, the Java Quick Starter extension will be removed.

Uninstalling manually

If you can't remove an extension from Firefox using the other methods described above, you can manually remove it. First navigate to the folder where extensions are installed:

1. Open your profile folder:

   At the top of the Firefox window, click on the Firefox button, go over to the Help menuOn the menu bar, click on the Help menuAt the top of the Firefox window, click on the Help menu and select Troubleshooting Information. The Troubleshooting Information tab will open.Click the menu button , click help and select Troubleshooting Information. The Troubleshooting Information tab will open.

2. Under the Application Basics section, click on Show FolderShow in FinderOpen Directory. A window with your profile filesfolder will open.
Note: If you are unable to open or use Firefox, follow the instructions in Finding your profile without opening Firefox.
3. Open the extensions folder inside your profile folder. Inside the extensions folder there are folders or XPI files for each extension and theme you have installed.
4. To determine which folder or XPI file corresponds to the extension you want to uninstall, return to Firefox and the Troubleshooting Information tab.
5. In the Extensions section, find the extension you want to remove and note the string in the ID column.

6. At the top of the Firefox window, click on the Firefox button and then select ExitAt the top of the Firefox window, click on the File menu and then select ExitOn the menu bar, click on the Firefox menu and select Quit FirefoxAt the top of the Firefox window, click on the File menu and select Quit.

   Click the menu button and then click ExitQuit .

7. Delete the folder or XPI file that corresponds to the extension ID you noted above.

Globally installed extensions

In rare cases, extensions are installed globally, into the Firefox installation folder. See this Mozilla Developer Network article for more information. Follow these steps to remove a globally installed extension:

Based on information from Uninstalling add-ons (mozillaZine KB)