My laptop has stopped playing sound?

Dell Laptop Speakers not playing music, but they are working?

• The laptop speakers were off while the threatre system was plugged into the audio jack (as expected). But when I unplugged them, normally the laptop speakers would come on still playing whatever music was playing on the comptuer. But it didn't. I ran the Dell System tool from CD (not in Vista), and the speakers worked under its Audio Test, that is there is sound coming out of them. So now my laptop speakers has stopped playing any music, even I know it still works. (no audio jack plugged in)

• Answer:

  Did you try going to the sound control and see if your sound has been muted