Some items shown in about:config are settings by Add-ons; you will need to investigate those by *visiting the home page for the Add-on (listed along the right side of that Add-on's page at https://addons.mozilla.org/ *posting on the forum (if it has one) for the Add-on(s) *sending an e-mail to the developer of that Add-on, if an e-mail link is available **on the Add-on's page at https://addons.mozilla.org/ (along the right side of the page) ** or by clicking the developer's name on the Add-on's page at https://addons.mozilla.org/ Some standard Firefox preferences are on the following page. I am not sure that the list is current and is most likely not a complete listing. Be careful making changes. Keep track of the original setting for each one that you change so that you can reverse the change if necessary. Some changse may require exiting then restarting Firefox. *http://kb.mozillazine.org/Firefox_:_FAQs_:_About:config_Entries *Also see --> http://kb.mozillazine.org/About:config '''If this reply solves your problem, please click "Solved It" next to this reply when <u>signed-in</u> to the forum.'''