Let me start off by saying it used to work and now I dont know whats going on with it. I have a Geforce GT 430 graphics card in my Dell Optiplex GX620 and im using the HDMI output to display it on my Panasonic Viera TV. The picture is just fine but its the audio i'm having an issue with. I've tried everything i can think of to fix it but nothing. I get sound through the computers built in sound (SoundMAX Integrated Digital Audio) but even tho I have the Panasonic-TV selected as default playback device and it shows check marked there is no sound. When I right click and try to test it I get that error saying that it might be in use by some other application or something. I dont understand what could be using it? I've tried disabling everything but it, but no luck. All my drivers are up 2 date and i'm on Windows 7 64 bit. It used to work but for some reason I can only get the sound to come from the integrated audio....what am I not seeing here?