Hello

https://support.mozilla.org/en-US/questions/1573654 ?

Go to https://ftp.mozilla.org/pub/firefox/releases/115.14.0esr/ Or Go to https://archive.mozilla.org/pub/firefox/releases/115.14.0esr/

Open the directory win32/, or, open the directory win64/, it depends on your operating system, the Firefox that you have installed. Next, download in your language, Firefox Setup 115.14.0esr.exe

https://connect.mozilla.org/t5/firefox-labs/thank-you-for-your-win7-support/td-p/120001

The old Fx 115.14.0esr released back on August 6, 2024 is vulnerable;e as it does not have the security/stability fixes since as the Fx 115.34.0esr is the current. The old 115 ESR channel only gets stability/security fixes and no new features so there is no good reason to use the old 115.14.0esr over 115.34.0esr.

https://www.mozilla.org/en-US/security/known-vulnerabilities/firefox-esr/