Microphone Disappeared

I can hear my hard drive through my speakers. Yes, it is irritating so I try now and then to "fix" it. I started disabling microphones but it didn't help. But the microphones disappear from the sound panel so how do you get them back?

I used this answer and it worked. Basically you Windows search within Control Panel for "audio" and find the "Troubleshooting" section and run "fix audio". It will find the missing microphones and you can re-enable.

I probably could have just gone to "device manager" and enabled. That was going to be my next try.

Thank you Dave Foord for the answer.

As to fixing the sound from the mouse and hard drive? I have no way of disconnecting the ground from my speakers but that seems to be the answer found here.