Goto this link (http://support.asus.com/download/options.aspx?SLanguage=en)
and click on the 'Start' button in the bottom-left box entitled 'Model Automatic Detection.'
You will then be directed to the drivers page for your computer. Just select the appropriate operating system. If there is no 'Windows 7' option, select 'Windows Vista.'
Expand the 'AUDIO' option and download the one at the top by selecting the link underneath it called 'Global.'