Audio Tips and Hacks for Windows
Microphone input set to 0%
Some driver updates and changes to Windows can cause your microphone input to be set to 0%. Symptoms of this issue include no level indicator when testing your microphone in the Windows Settings page or in an application such as Discord. The solution to this problem is to set the level back to a value greater than 0% in the Sound Control Panel.
This setting will be found in the Recording device's properties Level tab.