MagicDragon: Is this a new puter? or did you send yours in to the shop?

do some checking to make sure the speakers are all connected properly.. in the right socket..
Then.. if that isn't it.. you may want to..

Go to Control Panel/System Properties/System/Hardware/Device Manager if you notice a yellow ? next to anything then something isn't working correctly.. you would then just click on what it is and go into their properties.. where it tells you how to fix it..