Mozilla recommends launching the Windows wizard from Options>Set Firefox as default, which launches the Windows settings dialog, which..wait for it..does not even show Firefox in its list:
I tried to bring up the “Set defaults by app”, but again, no Firefox in the list! It appears that the Settings>Choose defaults thing is seriously botched.
However after a lot of hair pulling, to my surprise, I found another place to set Firefox as default. It appears that while integrating Windows 8 and 7 like features into Windows 10, Microsoft has duplicated this option, and the proper place to do this is to just type the following into the addressbar of Explorer:
Control Panel\All Control Panel Items\Default Programs\Set Default Programs
Within that Window, in one click, Firefox can be set as default. Actually this is the same settings screen that shipped with Windows 8 and 8.1 and works just fine:
Joel G Mathew, known in tech circles by the pseudonym Droidzone, is an opensource and programming enthusiast.
He is a full stack developer, whose favorite languages are currently Python and Vue.js. He is also fluent in Javascript, Flutter/Dart, Perl, PHP, SQL, C and bash shell scripting. He loves Linux, and can often be found tinkering with linux kernel code, and source code for GNU applications. He used to be an active developer on XDA forums, and his tinkered ROMS used to be very popular in the early 2000s.
His favorite pastime is grappling with GNU compilers, discovering newer Linux secrets, writing scripts, hacking roms, and programs (nothing illegal), reading, blogging. and testing out the latest gadgets.
When away from the tech world, Dr Joel G. Mathew is a practising ENT Surgeon, busy with surgeries and clinical practise.