Hello Other similar discussions. https://support.mozilla.org/en-US/questions/1526872

The old Firefox 115 ESR has already been supported far longer of all Firefox versions over the years as you can see at https://www.mozilla.org/firefox/releases/ Firefox 115 ESR was originally going to end as of 115.15.0esr released back on September 3, 2024 but then Mozilla decided to support the EOL Windows 7, 8, 8.1 and macOS 10.12, 10.13, 10.14 for a while longer in two extensions since. The last time people were asking for a old EOL OS to be supported for another two years was with Windows XP/Vista and Firefox 52 ESR in which WinXP/Vista was supported for over two years longer compared to the Chrome/Chromium browsers at the time. An option you have is to look for a light Linux distro to perhaps dual boot with as you can then use current versions of Firefox. Avoid say KDE and Gnome and use say Xfce or Mate for desktop environment. A downside though is unless you use a Long Term Support or LTS version of a Linux distro, they tend to only get package updates for as little as say 2-3 years before being EOL.