Open Settings
Click System
Click Sound
Select your input device under Input
Click Device properties
Adjust the Input volume slider
Open Control Panel
Click Hardware and Sound
Click Sound
Open the Recording tab
Select your microphone
Click Properties
Open the Levels tab
Adjust the Microphone level slider
Adjust the Microphone Boost slider if available
Click Apply
Click OK
Open the audio app or driver software if your device includes one
Adjust gain in the app or driver settings
Open Device Manager
Expand Audio inputs and outputs
Right-click your microphone
Click Update driver
Restart your PC if gain changes do not appear