I have a Dell E6540 and Lync (office365) gives a message that it does not recognize an audio device.
things I have tried
1) update Bios
2) update all drivers using Dell command update and Dell drivers update page
3) delete drivers so that it has to reload them
4) check microphone settings under sound
5) make sure power management is not turning the audio device off
6) plug in external head set (I would prefer if the factory installed microphone worked instead)