You can find your addons that you have install using "'''Ctrl+Shift+A'''" or from the tools menu. Next click on the puzzle piece (if your screen is wide enough you will see it) marked as "'''Extensions'''". What is add-on name, there is no indication of it anywhere in your question, and can't really tell if you can't find the extension itself or where to invoke use of it. If I have the add-on myself, you may find the information you need in my notes. :http://dmcritchie.mvps.org/firefox/firefox.htm#ext_table Many of the extensions have additional customizable options, all have disable/enable, more information (about ...), and update, which you can see by right clicking on the extension as found in the listing found with Tools, Addons or on the Find Updates button at the bottom of the Extensions list. Extensions can be invoked in many different ways so I have tried to identify where you invoke them from, such as from the right-click (context menu), Tools menu, Edit menu, View menu, and even the History menu(Go menu). Options are usually set in the Extension list (Tools, Add-ons, select ext, options), but some are in the menus just mentioned.