I would call tech support, but my service contract is up. I can't get any sound on my computer. In my 'Sounds and Multimedia Properties' box, under 'Sound Volume', there's the bar you can move from low to high, but I can't move it. 'Low' and 'High' are grayed out. I do have a sound card. What are the possible problems? I know there's a really simple answer to this; I just can't figure it out.