Using another computer, Download Firefox Full Version For All Languages And Systems onto a thumb drive. After, plug the thumb into your system. As of Firefox 53 in March 2017, WinXP and Vista won't be supported any longer. http://www.ghacks.net/2016/09/27/firefox-53-no-support-for-windows-xp-or-vista/ https://support.mozilla.org/en-US/kb/end-support-windows-xp-and-vista?cache=no https://support.mozilla.org/en-US/kb/install-older-version-of-firefox?cache=no Be sure to read everything here. If you still want to downgrade, look under; '''I still want to downgrade.''' Click the '''Directory of other versions and languages''' link. Look for the directory of the version that you want. But, remember that old versions may have security issues. You should also check out [https://www.mozilla.org/en-US/firefox/organizations/ Firefox; Extended Support Release] {web link} [https://www.mozilla.org/en-US/firefox/organizations/notes/ ESR Notes] [https://www.mozilla.org/en-US/firefox/organizations/system-requirements/ System Requirements]

I found the older versions, do not see an EXE

This is a bench machine that runs local 99.9% of the time, only need to go to trusted sites every now and then to look up error codes.

I got it figured out, THANKS!! This is a bench machine that runs local 99.9% of the time, only need to go to trusted sites every now and then to look up error codes.

I am glad to hear that your problem has been resolved. If you haven't already, please select the answer that solves the problem. This will help other users with similar problems find the solution more easily. Thank you for contacting Mozilla Support.