1393387 - Some registry folders, values and data are not deleted after uninstalling Firefox

Status: NEW

(Firefox :: Installer, defect, P5)

Description

[Virtual_ManPL [:Virtual] 🇵🇱 - (please needinfo? me - so I will see your comment/reply/question/etc.)]

Some registry folders, values and data are not deleted after uninstalling Firefox.

Some of them are:
[HKEY_CURRENT_USER\Software\Mozilla]
[HKEY_CURRENT_USER\Software\Mozilla\Firefox]
[HKEY_CURRENT_USER\Software\Mozilla\Firefox\Crash Reporter]
[HKEY_CURRENT_USER\Software\Mozilla\Firefox\TaskBarIDs]
[HKEY_LOCAL_MACHINE\SOFTWARE\Mozilla]
[HKEY_LOCAL_MACHINE\SOFTWARE\Mozilla\Firefox]
[HKEY_LOCAL_MACHINE\SOFTWARE\Mozilla\Firefox\TaskBarIDs]
[HKEY_LOCAL_MACHINE\SOFTWARE\Mozilla\MaintenanceService]
[HKEY_LOCAL_MACHINE\SOFTWARE\mozilla.org]
[HKEY_LOCAL_MACHINE\SOFTWARE\mozilla.org\Mozilla]
[HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Mozilla]
[HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Mozilla\Firefox]
[HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Mozilla\Firefox\TaskBarIDs]
and it could be more others

Comment 1

[Molly Howell (she/her) (no longer active)]

There are all individual cases and are going to have to be addressed separately.

- TaskBarIDs should be empty if all copies of Firefox have been uninstalled. We're not doing anything to get the empty key removed though, and I agree that's an issue, but a very minor one.
- The Crash Reporter key isn't created by the installer, and I don't think the uninstaller should be removing it. It looks like the way that key gets used means that it needs to survive an uninstall.
- The mozilla.org key is a bit of a mess and handling it properly isn't going to be worth the effort to support the external software that requires it (since that appears to be mainly the Java plugin, which we no longer support). In fact I'd like to investigate removing it altogether, but that's not a priority.
- The MaintenanceService key is intentionally left alone because the updater needs to know whether a maintenance service installation was ever attempted, even if it was for a different copy of Firefox.

And of course all of those keys are expected to exist in 32-bit or 64-bit versions depending on the build that was installed, and in either HKCU or HKLM depending on whether the installer had admin rights (but Crash Reporter is only ever in HKCU because the browser creates it and not the installer).

So I think the only actions that need to be taken are:
- The uninstaller should remove TaskBarIDs when it is empty.
- Investigate dropping the mozilla.org key (meaning, stop updating it and have the uninstaller unconditionally remove it).

Neither of those seems like a high priority thing or like a privacy issue; I'd be curious to hear why you tagged this bug as major and added the privacy keyword, in case there are other issues I'm not seeing.

Comment 2

[Virtual_ManPL [:Virtual] 🇵🇱 - (please needinfo? me - so I will see your comment/reply/question/etc.)]

I tagged this bug as "major", because uninstaller doesn't do its work completely, so major feature of uninstallation is broken, as there are still some unneeded bloat left, which is not cleaned and not removed completely in registry folders, values and data (omitting which Firefox component created that thing).
That's why I added "privacy" tag, as someone who could get access to registry, would see that Firefox was installed on that PC.
And using some external registry cleaners in most cases could break other software and it's mostly just snake oil, so no point recommending them to users as workaround, better fix Firefox uninstaller.
But feel free to change importance and keywords, as I done it by user and tester point of view.

Thank you very much for looking into it! :)

Comment 3

[Molly Howell (she/her) (no longer active)]

By that standard I think every bug that's a defect report would be major ;)

Leaving these entries around is definitely a bug, but it shouldn't be causing any problems in practice, with the exception of the privacy angle you mentioned, which I think is pretty minor. So I'm giving this one a low priority; I don't plan on working on it myself, but I would be happy to review a patch.