download and install the lastest realtek driver from the realtek website and restart your laptophttp://www.realtek.com.tw/downloads/downloadsCheck.aspx?Langid=1&PNid=14&PFid=24&Level=4&Conn=3&DownTypeID=3&GetDown=false
then go into Control Panel> Hardware and Sound> Sound
under the Forth Tab Called "Communications" put the dot into "Do nothing".
then under the "Sounds" tab change the "Sound Scheme" to "Windows Default" and click apply.
Next go to the "Playback" tab and make sure your realtek audio is set as your default audio device.