Microphone level is not manually adjusted – Windows includes a toggle that should allow you to override any application that might be adjusting the microphone level automatically.In this case, you should be able to resolve the issue by disabling exclusive mode or by booting in clean mode to identify the culprit.

If this scenario is applicable to your situation, you should be able to resolve the issue by accessing the Friends List settings and disabling Automatic Volume/gain control. In this case, you should be able to resolve the issue by disabling the automatic microphone adjustment settings.