Details like websites remembering you (log you in automatically) are stored in a cookie. *Create a cookie 'allow' exception to keep such cookies, especially in case of secure websites and when cookies expire when Firefox is closed. *Tools > Options > Privacy > "Use custom settings for history" > Cookies: Exceptions In case you are using "Clear history when Firefox closes": *do not clear the Cookies *do not clear the Site Preferences *Tools > Options > Privacy > Firefox will: "Use custom settings for history": [X] "Clear history when Firefox closes" > Settings *https://support.mozilla.org/kb/remove-recent-browsing-search-and-download-history Note that clearing "Site Preferences" clears all exceptions for cookies, images, pop-up windows, software installation, passwords, and other website specific data. Clearing cookies will remove all specified (selected) cookies including cookies with an allow exception that you would like to keep. ----- Note that your System Details List shows multiple Flash plugins. *Shockwave Flash 15.0 r0 *Shockwave Flash 14.0 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\