pat mcgroin :
go here and reload direct x.
I think it will fix you up.
http://www.microsoft.com/downloads/details.aspx?displaylang=en&FamilyID=2da43d38-db71-4c1b-bc6a-9b6652cd92a3
I tried that already. It didn't worked. Somehow I made it and sound works, but after hours of trying. In I found out that Asus is very complicated for these things such as system reinstall, if you don't have original drivers, it a big trouble. Finaly I Installed High Definition Audio bus driver and sound works but even after that, it has something missing and it isn't completed, but I dont care