If it works, don't break it. I have no idea really. It is for 1 thing only https://support.mozilla.org/en-US/kb/what-mozilla-maintenance-service Just keep a eye on the Extended Version page by mousing over a download button once in awhile to see what version is on the download page and if it matches or is above yours. if not getting updates think you would have to remove and reinstall. https://www.mozilla.org/en-US/firefox/organizations/all/

Please let us know if this solved your issue or if need further assistance.

The MMS version that is installed is always the version that comes with the most recent Firefox version you have ever installed. So it looks that you have once used Firefox 53.0.3 and then installed the Firefox 52 ESR version. If you revert to an older Firefox version then this leaves the installed MMS version. There is nothing wrong with keeping this newer version of MMS.

cor-el said

The MMS version that is installed is always the version that comes with the most recent Firefox version you have ever installed. So it looks that you have once used Firefox 53.0.3 and then installed the Firefox 52 ESR version. If you revert to an older Firefox version then this leaves the installed MMS version. There is nothing wrong with keeping this newer version of MMS.

Actually I was up as high as Firefox 55.0.3 before reverting to 52 ESR (and had to go through some machinations using a backup of a 54 profile, since as you know 55 profiles are incompatible with earlier builds). So I'm not sure how I ended up with 53.0.3 for MMS, but thanks for your reply that indicates this should not be a problem. (As an aside, I think for awhile I had *two* copies of MMS installed at once, but forgot I could scroll further over in the Win 7 uninstall/change programs to see a version number.)

There may have been 32-bit and 64-bit Firefox versions installed and 53.0.3 was the last version you kept. In case you once switched from 32-bit to 64-bit or the other way around then MMS likely got replaced.

cor-el said

There may have been 32-bit and 64-bit Firefox versions installed and 53.0.3 was the last version you kept. In case you once switched from 32-bit to 64-bit or the other way around then MMS likely got replaced.

Yes, I did do some switching between 32-bit and 64-bit Firefox versions before settling on 32-bit as smoother-running (in my case, anyway).

I take it from your comments that even if the 53.0.3 MMS *was* part of a 64-bit installation, you still feel it's OK to keep that simultaneously with Firefox 52.4 ESR 32-bit. Correct?

Yes, a more recent MMS version can handle older Firefox versions. If you would update again then you will get a new MMS version.

cor-el said

Yes, a more recent MMS version can handle older Firefox versions. If you would update again then you will get a new MMS version.

Thanks, but I should have been clearer that part of my followup question was whether whether it is OK to "mix" a 32-bit Firefox installation with an MMS that might have been generated by a 64-bit Firefox installation (separate from the question of version numbers, which you addressed).

Just noticed another wrinkle: In Options/Updates the option "Use A Background Service To Install Updates" is completely missing. Yet I have another computer that also has Firefox 52.4ESR 32-bit, and on that one the "Use a Background Service" option *is* offered. Probably *not* coincidentally, on that one the MMS version matches the Firefox version, i.e. it is 52.4 (instead of 53.0.3).

It so happens that I don't want automatic updates anyway. But if I *did*, doesn't the missing option suggest that the higher-version MMS wouldn't work for me?

I assume that "Use A Background Service To Install Updates" is only present when this service is installed. Then you can choose to use it or not. When MMS isn't installed then it wouldn't make sense to have this choice.

• maintenanceservice_installer.exe
• about:config: app.update.service.enabled