It is also recommended to choose 'custom installation' during firefox setup, and not to install 'maintenence service' from there.

Enable the internet access after saving new settings and you will be good to go. To avoid automatic updates, don't forget to disable the internet connection prior to installing version 52, and disable the automatic updates completely from firefox preferences> advance> updates tab. Note2: Since the firefox ESR channel has also entered into 'quontum' releases where many older add-ons are no longer compatible, We have also included the links below to download the last release of firefox legacy version, which was 52.9.0, for both 32 and 64bit operating systems, for those people who were looking to stay with older version due to add-on compatibility problems. Note: These links are logical, means that you will always get the latest version of firefox of the current time. These are mostly used in the organizational environments, where major upgrades are not necessary, or when you want to stay with an older version while keeping the browser's security up-to-date. Here are the mozilla firefox extended support releases.

Firefox esr 52 download