I was watching some anime, when suddenly the sound stopped being heard. I thought it was because I hadn't turned my computer off in all day long. So, I decided to shut it down for some time, and when I turned it on again, I found out it was still the same problem. I also thought it was just the webpage, but apparently, it doesnt work on youtube either. I ran dxdiag, and the diagnosis confirmed my speakers were fine, and that there were no problems at all with them. But still, no sound can be heard coming from computer. What's the matter?