When playing videos using VLC or MPC-HC, the videos play normally but without sound. I've disabled and re-enabled the appropriate files without success. Winamp, also lost its sound at the same time. However, when using Audacity, it produces sound perfectly. Likewise when watching stuff on Youtube.

To my way of thinking, it appears the loss of sound is not the fault of Windows but rather something to with a third party but what that party is I'm unable to determine. Some hints would be very much appreciated. Thank you.