Uninstalling add-ons

The New Extension Manager

The Extension Manager in Firefox 0.9+ and Thunderbird 0.7+ is capable of uninstalling extensions (Tools -> Extensions).

If you can't uninstall an extension with the new extension manager, it means that:

• The extension in question is "locked" and the uninstall button/menu item is disabled'. An example of such an extension is the DOM Inspector. You'll have to unlock it before uninstalling.
• The extension was not packaged for the new extensions manager (it has a red "generic" icon or not listed in the EM at all). You'll have to uninstall it manually or using an extension uninstaller (see below). The general recommendation is: create a new profile for Firefox or Thunderbird and only install the repackaged extensions in it.
• If the extension repeatedly shows "This item will be uninstalled after you restart Firefox" even after restarting, do not use the uninstaller extensions. Either start a new profile or try uninstalling manually (see below).

Uninstaller Extensions

These extensions are useful for Firefox (pre-0.9), Thunderbird (pre-0.7), and Mozilla Suite users.

Do not use these extensions if you have the "This item will be uninstalled after you restart Firefox" message in the extension manager! Start a new profile or follow the steps in "Uninstalling manually" section instead.

• Extension Uninstaller by Jeremy Gillick, an extension built from the ground up to uninstall extensions. Discuss this in the forums. Mozilla Update links: [1] [2]
• Uninstaller (discontinued) by Chris Pederick. An extension which also automates this task. Discuss this in the forums.

Uninstalling manually

It is highly recommended that you disable or ignore the profile or create a new profile instead of uninstalling manually due to the risks and tediousness involved.

It's a good idea to make backups of your profile folder before deleting or changing anything in case something goes wrong.

Removing profile-installed extensions

You'll need to know the internal "short name" of the extension you're uninstalling. You can find it by searching for the full name in the chrome.rdf file (see below).

1. Exit Firefox or Thunderbird and make sure it is not listed in your process list (Ctrl-Alt-Delete on Windows).
2. Browse to your profile folder.
3. Mozilla users: Remove the profile folder/chrome/[shortname].jar file.
   All other users: Remove the profile folder/extensions/{extension-GUID} directory. You can find the GUID by looking in extensions.rdf file or by searching for [shortname].jar file in your Extensions directory.
4. Delete compreg.dat and xul.mfl (it may be called slightly differently) files. They will be recreated on next browser start.

Optional steps

Your extension will now be uninstalled, but there are a few (harmless) remnants left, so the following sections are optional.

1. Edit files in Profile Folder\chrome\overlayinfo. Find those that contain [shortname] inside them and remove entries, that look like this:

   <RDF:li>chrome://[shortname]/[path/to/file]</RDF:li>

2. Edit the profile folder/chrome/chrome.rdf file. Remove all entries referencing the extension. See the list of possible entries.
3. Firefox and Thunderbird users: Edit profile folder/extensions/extensions.rdf. Remove the entry that looks like this:
   

   <RDF:Description RDF:about="urn:mozilla:extension:{[GUID]}"

em:name="QuickNote" [more info]> [more info] <em:targetApplication RDF:resource="rdf:[junk]"/> </RDF:Description>

1. Firefox and Thunderbird users: Edit components.ini and defaults.ini and remove the lines that contain the GUID of the extension being uninstalled. They are located in the root of your profile folder.
2. Remove extension-related preferencess from prefs.js.

Some extensions also create extra files on your hard drive. For example, Menu Editor stores its data in a menuedit.rdf file in your profile folder and TBE uses tabextensions.js. You might want to remove those too.

The list of possible chrome.rdf entries

• <RDF:li RDF:resource="urn:mozilla:package:[shortname]"/>

• <RDF:li RDF:resource="urn:mozilla:locale:[locale]:[shortname]"/>

• <RDF:li RDF:resource="urn:mozilla:skin:[skin]:[shortname]"/>

• <RDF:Description RDF:about="urn:mozilla:["locale"/"skin"]:[locale/skin]:[shortname]"

c:baseURL="[path]"> <c:package RDF:resource="urn:mozilla:package:[shortname]"/> </RDF:Description>

• <RDF:Description RDF:about="urn:mozilla:package:[shortname]"

                c:baseURL="[path]"
                [a lot more info]>
 <c:selectedLocale RDF:resource="urn:mozilla:locale:[locale]:[shortname]"/>
 <c:selectedSkin RDF:resource="urn:mozilla:skin:[skin]:[shortname]"/>

</RDF:Description>

Removing a globally-installed extension

Firefox 0.9+ and Thunderbird 0.7+, by default, install their extensions into the profile folder, so this section will not apply to those users. Mozilla users are still able to install their extensions globally (that is, in their Mozilla application folder and not their profile folder).

1. Exit Mozilla.
2. Browse to the "chrome" directory of your Mozilla application directory (usually C:\Program Files\Mozilla Firefox\chrome for Windows users; for Mac users, Ctrl-Click the Mozilla Application folder package and select "Show Package Contents" and browse to /Applications/Mozilla.app/Contents/MacOS/chrome).
3. Modify chrome.rdf and the files in your "overlay" folder as described above in the "Optional steps" section.
4. Delete [extensionname].jar (or the [extensionname] directory if it has one).
5. Remove every line with a reference to the extension's name from installed-chrome.txt. Usually there are two: one to the content and one to the locale.
6. A few extensions might use additional files. TBE, for examplem has a "tabextensions.js" in application folder/defaults/pref/ to store its defaults in. Search through your application dir for such files and delete them.