This is a Firefox version that is specially branded by Yahoo, so it is up to Yahoo to provide a 64-bit version of their program. On the Mozilla servers there are 32-bit and 64-bit Firefox versions available. *https://www.mozilla.org/en-US/firefox/all/ Keep in mind that only the Shockwave Flash plugin and Silverlight plugins are enabled for 64 bit Firefox versions for Windows. If you need to use other plugins like Java or media players then stay with a 32 bit Firefox release. *http://www.ghacks.net/2015/11/25/firefox-64-bit-to-support-microsoft-silverlight-after-all/ ---- Note that the System Details List shows that you have multiple Flash plugins. * Shockwave Flash 19.0 r0 * Shockwave Flash 24.0 r0 You can find the installation path of all plugins on the <b>about:plugins</b> page. *http://kb.mozillazine.org/Issues_related_to_plugins#Identifying_installed_plugins You can check the Flash player installation folder for multiple Flash player plugins and remove older version(s) of the plugin (NPSWF32) and possibly (re)install the latest Flash player. *(32 bit Windows) C:\Windows\System32\Macromed\Flash\ *(64 bit Windows) C:\Windows\SysWOW64\Macromed\Flash\ You can download the latest Flash player version (24.0.0.194) for Firefox on this page: *https://get.adobe.com/flashplayer/otherversions/

The en-US Firefox from www.mozilla.org/firefox/all/ comes with Yahoo as the default search engine and is available as 32-bit and 64-bit (Win64) for Windows.