Running an old Firefox instance using a profile created by a modern version of Firefox will corrupt your bookmarks, history, and passwords. Press Windows Key + R to open the Run dialog.
before launching the newly installed legacy Firefox for the first time. Launch Firefox. Download Firefox 12-51 52 Esr
Download Firefox 12-51 52 ESR: The Ultimate Legacy Browser Guide Running an old Firefox instance using a profile
Navigate to the official Mozilla FTP server archive (Directory of /pub/firefox/releases/). or accessing sensitive personal data.
For Firefox 52 ESR, which was released in April 2017 and supported until August 2018, users can still find it through the following methods:
Never use a legacy browser for banking, shopping, or accessing sensitive personal data.