Generally this happens from outdated sound card drivers. Be sure to visit your manufacturers website to see if there are new drivers out there for your sound card. If you are unsure what sound card is installed in your system, do the following: Click on the start button, click on run and type DXDIAG. Click on the SOUND tab to display the name of your sound card. On the right side you will also see the PROVIDER of your sound card ie: creative Technology. In this section you can also test your sound by clicking on "Test Directsound". If all else fails, within the SOUND tab, you can set the "hardware sound acceleration" level to a lower level, which may help clear up your sound issues.