Are you asking for how to download the current version of Firefox for Windows 7 ? See https://www.firefox.com/download/all/desktop-esr/ then pick Windows 64-bit or Windows 32-bit then the language then click on [Download ESR 115] to download the current Firefox 115.30.0esr. The Firefox 115 ESR is planned for updates till 115.33.0esr next year unless Mozilla extends updates again. https://support.mozilla.org/en-US/kb/firefox-users-windows-7-8-and-81-moving-extended-support