Firefox 116.0 and later including the current Firefox 132.0 Release and Firefox 128.4.0 ESR requires Windows 10/11 and macOS 10.15+ to run. For the eol Windows 7, 8, 8.1 and macOS 10.12, 10.13, 10.14 OS users the most current version you can run is Firefox 115 ESR which is currently at 115.17.0esr https://www.mozilla.org/firefox/115.17.0/releasenotes/ Firefox setup 115.17.0esr is below as each folder is the language. You may likely want one of the "en-" https://archive.mozilla.org/pub/firefox/releases/115.17.0esr/win64/ https://archive.mozilla.org/pub/firefox/releases/115.17.0esr/win32/