hello venusandino - this might be caused by adware. if your manual changes don't 'stick', please look out for any suspicious extensions (like 3rd-party-toolbars or things you have not installed intentionally or don't know what purpose they serve) presently installed under '''firefox/tools > addons > extensions''' or the programs section of the windows control panel and remove those entries. afterwards you could install the search reset addon - it will revert the most common customziations those adware programs do in firefox back to the default: https://addons.mozilla.org/firefox/addon/searchreset/ [[Remove a toolbar that has taken over your Firefox search or home page]] [[How to fix preferences that won't save]]