sir,
I assume you followed these troubleshooting steps:
https://answers.microsoft.com/en-us/windows/forum/windows_8-hardware/my-headset-microphone-not-working-in-windows-8/f4f1ad12-e7ea-4ffb-ac88-df5eed3298e6
Beyond that, I would recommend disabling all of your recording devices, rebooting and...