https://archive.mozilla.org/pub/firefox/releases/115.0esr/win32/en-US/Firefox%20Setup%20115.0esr.exe You can replace 115.0esr with 115.13.0esr (the final Windows 7 build) or change en-US to your locale code (e.g., de , fr , ja ). If this Windows 7 machine is used for browsing the modern web, strongly consider upgrading to Windows 10/11 or Linux. Firefox 115 on Windows 7 is frozen in time and missing security patches for known vulnerabilities.