First, go to Start, type dxdiag and open the utility. Click the Sound tab, check your sound card model and download and install the latest drivers available from the developer web page. After that, right-click on the sound icon from System Tray and press Playback devices. Right-click anywhere in the Playback tab and check the Show Disabled Devices option. After that, open the device options and select Use this device (enable) as Device usage. If the problem persists, I suggest you download and install the latest version of the software.