Issues have been previously linked to the McAfee Site Advisor extension. Try to disable it and see if the problem persists. http://service.mcafee.com/faqdocument.aspx?id=TS100162 How to uninstall SiteAdvisor To disable it: Type "about:addons" in the Location bar Find the extension and click on its "Disable" button ------------------- '''https://support.mozilla.org/en-US/kb/how-to-fix-preferences-wont-save''' Note: Some software, like Advanced SystemCare with Surfing Protection, can protect files in the Firefox profile folder against changes. If you have such software then check the settings or uninstall this software. --------------- Type '''about:addons'''<enter> in the address bar to open your Add-ons Manager. Hot key; '''<Control>''(Mac:<Command>)''<Shift> A)''' In the Add-ons Manager, on the left, select '''Extensions.''' Remove Bing '''Anything.''' Now do the same in the computers Programs Folder. '''Windows:''' Start > Control Panel > Uninstall Programs. '''Mac:''' Open the "Applications" folder. '''Linux:''' Check your user manual. ------------------ After the problem is fixed, Bookmark and use this; Download the '''[https://addons.mozilla.org/en-US/firefox/addon/searchreset/ Mozilla Search Reset]''' {web link} This add-on is very simple: on installation, it backs up and then resets your search preferences and home page to their default values, and then uninstalls itself. This affects the search bar, URL bar searches, and the home page.