What Firefox version is the ''original firefox'' version and why do you want to install such an old Firefox 52 ESR ? *https://support.mozilla.org/en-US/kb/use-troubleshooting-information-page-fix-firefox You can install a portable (ESR) Firefox version to access websites that do not work with the current Firefox release. The portable version comes with its own profile folder and doesn't interfere with currently installed Firefox versions. *https://portableapps.com/apps/internet/firefox_portable *https://portableapps.com/apps/internet/firefox-portable-esr *https://sourceforge.net/projects/portableapps/files/Mozilla%20Firefox%2C%20Portable%20Ed./ See also: *https://support.mozilla.org/en-US/kb/recovering-important-data-from-an-old-profile