Can I ask are you using Realtek AC'97
linky poos Before you download, unistall all drivers and devices related to the Realtek AC'97. After download, extract all and then open 6213_Vista_APO. Scroll down until you see 'setup' (Application 59KB) and click on it. Let it do it's thing and Windows will recognize the device but DO NOT let Windows install the driver, let the Realtek setup. When it is complete, it will prompt to restart, so do it.
let us know how you do.
ps got to pop out be back about 4pm