Speakers are not "line in" devices. They connect to an output jack. "Line in" is for devices that input sound. As far as device "discovery" goes, this is usually a setting for your sound device that detects when something is plugged in or removed. I'd look for such a setting but cannot tell you where it would be. I have seen occasions when an installed driver was not compatible with the actual device and would mis-identify ports or have them incorrectly assigned. Since you're in the Win10 forum, I could suspect there are a lot of driver issues out there related to upgrades from previous Windows version that don't have the manufacturer's own driver installed. Maybe if you tell more about the PC hardware and if this is an upgraded computer rather than one built with Win10 installed, it would help someone come up with a good answer.
I just bought a headset, which now shows up in my speaker area, however I made a mistake and disabled my actual stereo speakers. I have rebooted a lot of times and they no longer show up in the active speaker list.
they are in Devices and Printers as line in (2 Hi Def audio Device), but there is no click box to re-enable them. I also unpluged the speakers from the computer hooping that after rebooting the system would find them. What am I missing? Thanks, Mike