Stereo Mix, Windows 7

What I am trying to do is to record a skype conversation, which requires that I record both what I say into my microphone and what comes through from skype. Some homework has shown me that the way to do this is by enabling stereo mix. However I have found that even with enabling it in my recording devices and setting it to the default, it does not want to record. Mind you, I can technically use stereo mix in Audacity, but it does not pick up any form of sound.

Does anyone know how to resolve this?

Audacity is not really suitable for recording Skype due to the way that Skype manages the sound system. See here for suggestions: https://forum.audacityteam.org/t/blank-spots-recording-skype/34380/2