Last night all of my files worked fine and I had no issues. This morning, I went to watch a video using windows media player and got an error stating that it couldnt play the video, the picture was there but it had no sound. I tried using VLC and again, no sound. While trouble shooting it with the windows help sidebar, I received a Skype call from my wife and could hear her just fine and even heard the skype ringing when she called.

I tested my sound using the mixer and could see that the green bar would move each time I hit test, but I would get no sound. I tried to update my drivers, but windows said that I already had the best available drivers for my hardware. Ive tried turning everything off, disabling and enabling the sound card and nothing has worked. I am confused and could use any advice. Thanks for your help!

Some of this is gong to be obvious but you tell of the woes and having tried everything.... well I assume ,that the default beeps work. If they dont then it can be
a broken sound card
loose connection
broken speaker
muted sound somewhere in the system software
incorrect driver

or finally and I have had this happen frequently (as I use a number of sound systems / inputs etc) that somle other device is hogging the sound system an d not allow anything else to get a look in.

*On my machine there is a midi music interface and ponce that gets hold of the 'default' sound system only signals that come from the midi interface actually produce sounds (all the rest seem dead)
It is worth your looking to see if there are any other 'sound' devices using the system and either disable or if they are USB (microphone, audio player, dvd player etc) disconnect.