I have an iMac(5k Retina, late 2014) and I have installed windows 10 via bootcamp. I have a Razer Kraken X that has a microphone.
So first of all let me say that the problem is not my headphones or my headphone jack. When I plug in my headphones in Mac OS everything works fine, sound and microphone. When I go to bootcamp however, My headphone audio works but the microphone does not work. When I plug in my headphones, the output device changes, but my microphone is still set to the default integrated mic. I've tried using a different headset with a mic but that same thing happens. I've tried uninstalling and reinstalling my drivers using windows support software from apple, same result. Windows just doesnt detect my mic. its not a privacy issue or the mic is disabled, ive tried all of those. my last resort is to buy an external usb soundcard or remove the bootcamp partition completely and reinstall windows.