Hi Aunty, I do not use Mac s and am not the best person to attempt an answer, but no on else has answered. It is probably more usual to configure Firefox when deploying it, furthermore such deployments may use ESR instead of the standard Release. * https://www.mozilla.org/en-US/firefox/organizations/faq/ <br/> Note the EWG mailing group * A popular method is using CCK. The software is free. The developer's site/blogs have a lot of information. (You may now need to subscribe - also free) https://mike.kaply.com/cck2/ ** (now out dated https://mike.kaply.com/2012/04/13/customizing-firefox-extensions-and-the-cck-wizard/) ** https://mike.kaply.com/?s=cck&submit=Search ** https://mike.kaply.com/?s=cck2&submit=Search * http://kb.mozillazine.org/Locking_preferences * '''https://developer.mozilla.org/Firefox/Enterprise_deployment''' I imagine your script method would do much the same as would be done manually if making these changes in a profile. * See [[Recovering important data from an old profile]] ** [[Home page with pipe character opens extra tabs when Firefox starts]] There are prefs.js & optionally the useful user.js files and the mozilla.cfg file mentioned in the linked articles, but Firefox does not use a config.js file in the profile.