https://support.mozilla.org/en-US/kb/update-firefox-latest-version

^ That isn't going to work on the versions of Firefox that come with Linux Distros. Linux Distros use their own programs Repositories along with their own update facility, which doesn't use what is built into Firefox for installing updates. Download the latest version from here - http://www.mozilla.com/en-US/firefox/all.html - ''note only the 32-bit version is available there.'' <br /> ''The 64-bit version is available here - http://ftp.mozilla.org/pub/mozilla.org/firefox/releases/25.0/linux-x86_64/en-US/ '' Then see this support article: <br /> https://support.mozilla.org/en-US/kb/install-firefox-linux https://help.ubuntu.com/community/FirefoxNewVersion/MozillaBuilds