I have a HTPC build with Windows7 (64bit) running on it. I have ATI Radeon HD 5700 Series on Gigabyte X58A-UD3R motherboard. The current set up is to have both audio and video going through HDMI out. I recently installed ASUS Xonar DS 7.1 to get the exclusive audio out from S/PDIF. However, after much tries, I have not been able to get it working (the audio will never come out through Optical S/PDIF and will pass through HDMI only). I did an extensive research on internet forums and found out that the only way it could work is somehow disable audio to come out through Radeon board (which forces it to go through HDMI). Could anyone tell me how could I make it work?