Hi Taz-D, the extensions with @search.mozilla.org are built-in to a large Firefox program file. They are not separate files that can be deleted. You can manage where they appear using the "One-click Search Engines" section of the Preferences page. See: [[Change your default search settings in Firefox]] I suggest simply unchecking them and not removing all of them. Some users have reported that if they remove all of the built-in search engines, Firefox always restores all of them at the next update.