text: It could be your sound card.... That happened to me on my Dell Laptop... Fortunately, I invested in the extended warranty.... In my Dell laptop the sound card is attached to the motherboard so they had to replace the whole thing...\n\nFirst go to START then ALL PROGRAMS then ACCESSORIES then ENTERTAINMENT then VOLUME CONTROL to make sure that you haven't accidentally mute anything.  \n\nIf you are still under warranty then call your computer company's help line.  If your warranty has expired then you might try the Geek Squad at Best Buy or someone like that..\n\nGood Luck!