Do nothing yet with downloaded file.
Go Start>Run, type in:
In Device Manager, click on a "+" sign next to Sound, video, and game controllers
Right click on Intel 82801EB ICH5 - AC'97 Audio Controller (it may be listed only as AC'97 Audio Controller)
Click Properties, then Driver tab.
Click Uninstall button.
Go back to downloaded 82801DB_DBM_DA_AC97.zip file.
Right click on it, click Extract all
It'll extract into very same folder.
Now, right click on oem34.inf file.