No audio coming in? Help needed

Running Vista Home.

Audio (Realtek Speakers) works fine on everything but Live Messenger. It
never worked on 8.1 so I tried upgrading to 8.5. Still doesn't work. People
can hear me fine and I can tell they are talking by the "volume bar" that
raises as they talk but I cannot hear them.

I tried using the audio/video setup but hear no sound when the button is
pressed. Also, the volume slider on the audio/video setup is all the way
down and goes down when I try to raise it up.

Can someone please help.