Windows 10 now decided to not let me use Firefox anymore as default browser, although in Settings Firefox IS indicated as the default browser, as it has been for many months now.
How can I FORCE Win10 to really restore Firefox as the default browser?
Have you checked your Default Apps setting ? (Settings->Apps->Default Apps).
Check the Options/Advanced/System Defaults in Firefox, as well, to over-ride. Then check in current default browser, to ensure it's disabled there. Reboot.
Tried System Restore 2x, continually re-setting in Firefox options many other things. Finally noticed in the default apps selection Firefox was there twice, clicked on one (as I had today done umpteen times!) .... and this time Firefox & Win10 made friends again.
Done/FIXED (so far, at least I now know it's fixable)
More clues
The issue showed up again and was solved again and I think I know the cause: I am using Classic Shell so WinX has some things stored in several places, for ex. Documents, User Documents, etc, (I am the only Admin.). One clue: Firefox is on the Taskbar and also on Desktop ... but a different version, perhaps from Firefox update or whatever (WinX gets easily confused with so many possibilities apparently).
Since Firefox was again NOT Default only on the only similar-seeming version on Desktop (no prob w/ the version on the Taskbar) I had to try different internal (to WinX/ Classic Shell, etc.) versions of Firefox to place on Desktop, dragging from Start Menu and other places.
THAT worked on the Firefox "versions" in both the Taskbar AND Desktop even though the Default App drop-down still shows TWO Firefox choices!
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