Sadly I don't have access to win10 at the moment, my win10 test laptop is.. under reinstall (windows10 broke, I tried to break it)
First, you cannot have TWO default recording devices.
Some ports can have feedback, For me (and my realtek soundcard) it tells if the port has that problem. (I've not seen it in my own use but they don't guarantee it)
the listen to this device tick allows you to hear what microphone hears.
Useful at times as far as testing goes and if your headphones nullify external voices (you don't hear yourself normally) or.. something. matter of taste really.
If said tick is in there, it is decent idea to test without.
most of the ports are auto configured (as speaker/mic/whatever else) based on what you plug in.
the ports mics are plugged into are color coded.
mainboard/sound card are unknown? well.. how about computer type then? since from that, it's insides can be found out too.
This part is mainly in case someone needs to know something more specific to help.
Recording software being used question was more like... Yes, you hear the sounds but not what you say from the mic. (might be a case of that listen to this device tick being missing)
Recording software being used question was more aiming at what you were doing when you were using said mic to.. I guess speak to someone or comment or.. something?
skype? playing a game? streaming it? recording gameplay with something?
and if it is any of those, were only you affected or was the final product also missing the sounds?