Windows 7 - No sound from speakers but showing sound graph on speaker control

I have an MSI 785GTM-E45 Mother Board. I have no sound coming from the speakers. Tried new speakers and still no sound. If I click on the speaker Icon on the bottom right it shows the speaker graph going up and down as sound is being produced. I tried the head phones and nothing coming from them either. I tried playing a CD and nothing from there either. I first noticed it when I was trying to play something from YOUTUBE and thought it might just be the site but then I tried off line as well. I am running Windows 7 Home Premium. This is the first day that I have noticed it. Thanks for any help. I have checked all the settings I can think of but probably have missed something somewhere.

Go to the Control Panel/Hardware and Sound and finally the Sound Panel. In the Playback section, set your "Speakers" as the Default Playback device (if it's not now set). Then see if you have speaker and/or headphone sound.