The strange thing is that when I go into "Set up audio and video devices" the microphone volume gauge picks up my voice. Not only this but I can have audio calls with friends and they can hear me. So it's clearly not a microphone driver issue (I can also use Windows built-in Voice Recorder without any issues). It also shows that WLM recognises my microphone AS working (as I can have audio calls). 

However, when I attempt to send a voice clip it says: The option to record voice clips is turned off.

This makes it seem like it's a choice...however when I go into Options...Messages. the ONLY bit about voice clips is under "Automatically accept when I receive" - this field, however, is faded out and I can neither tick or untick the box. 

Consequently, I can't receive voice clips either. 

Does anyone know why? Why can't I send/receive voice clips even though WLM acknowledges my mic. and speakers work....?