Your having an audio problem as what I can see with your description. You need to reset your sound device with your computer by reinstalling your audio component. You need to download the driver from the manufacturers website and reinstall the driver. after the installation you need to restart the computer. Please make sure to check if the audio was set to high volume and not to muted. It would be helpful if your going to consider the operating system of your computer before downloading any drivers since most of the computer manufacturers publish their computer drivers altogether on the internet with different operating system on a same page. To check on what operating system you are running with your computer, you may click start>right click computer> then choose properties. Your computer information will pop up on the screen.

Should you have any more questions, please feel free to ask.

Cheers~

There is a problem in your sound card. Just reinstall the audio drivers & it will work.
Regards
Manjeet