I have an Intel dq35jo motherboard with hd audio bus. Driver would not install, bad file message at time of install. I used Michelin's post for the beginning of the process, but he left out the final, "get you computer with audio" and working hd audio device in the the device manager step.
The initial steps:
Create a folder on your desktop caledl "backup" or anything you want
Go to the Start Menu and click on run
Type "regedit" and click OK
Expand HKEY_LOCAL_MACHINE, Expand SYSTEM, Expand CONTROLSET001
Expand ENUM
In here you should see a folder HDAUDIO
Highlight by clicking on
Go to File Export and save file to the folder you created on the desktop
Delete the folder in the regedit
resstart
Message will appear on start up that you have a missing driver.
Ignore this message and Install the driver that didn't work originally, this worked after me.
Another thing to mention is that most motherboards that has a hdAudio link also has the old ac97 connection which is to be used if you still have further problems. Simply open your case, pull out the hdAudio and replace with the other cord labeled ac97