Sorry, the forum seems to have removed my formatting!

• I have uninstalled, reinstalled,
• disabled auto updates
• disabled auto updates in about:config
• tried never going to the help/about page but instead about:support to validate the installed version
• Installed over the top
• Uninstalled and removed all mozilla folders from \users_name\appdata\local as well as roaming and locallow.
• Deleted all registry keys for mozilla and firefox that I could find
• Tried all steps here including the auto delete update file script https://support.mozilla.org/en-US/questions/1157765
• pretty much every combination of the above at once as well as rebooted between uninstalling and reinstalling.

You can only change the update channel by installing a full version or you may have multiple 32/64 bit versions installed that are accidentally started. A normal update doesn't affect the defaults/pref folder where the channel-prefs.js file is located that specifies the update channel.

Something weird must be going on if you change the update channel that often.

Firefox 52 ESR which is on the ESR channel will never update to a version on the Release channel whether it be the current 57.0.4 or the older 55.0 Release.

I agree you may likely have had both 52.5.3esr and 55.0.3 installed on Windows 7.

I only have the single instance installed, and I have thoroughly been through and removed everything , program files, program files (x86), app data and registry keys.