I have a ASUS K8V motherboard. It has Soundmax AD1980 on board sound card. After installing Windows Vista x64 I am not able to hear any audio. I am having a 2.1 speaker which was working before. When I had performed Vista setup, the AC97VIA sound driver was installed automatically. Upon reboot the system showed up some audio. There was audio on my speaker but there is no sound from S/PDIF. I had done a number of installation of Vista 64bit drivers but it does not work. While looking on web I found that it needs some kind of smwdm.sys file which is responsible to run the audio. It is not found. Is there a way I can download it. One thing I want to mention more here is, that this thing works quiet well on Windows XP x64 system.