Hi All, I have used these forums extensively in the past for both questions and answers, and this time I have a problem. I have used this same motherboard in 3 PCs, so I have something to compare with. I have a TF7050-M2 motherboard that I am using to watch ripped DVDs. This is my HTPC system. The system has Windows XP3 w/SP3 and WinDVD to watch movies. The way my home TV system is set up is via a multmedia receiver and switching system that selects satellite (SAT), DVD (DVD), Blu-Ray, etc. sources and sends the video and audio to the TV. The HTPC in has a 500GB internal HD. I recently removed the PC from it's setup to add an external USB hard drive to it for more storage. When I went to replace the HTPC, the videos were displayed properly, but there was no audio. Now comes the tricky part. I tried different settings for the audio because I didn't remember exactly what the audio settings were. My nephews who watched a lot more movies than I did said that when they set it up the way they remember, there was still no audio. The HTPC connected to my multimedia receiver with an HDMI cable and 2 RCA cables. The receiver was set to "DVD" to watch the HTPC. I removed the PC to my workbench and opened up Device Manager. There was a yellow question mark and exclamation mark next to the "Audio device on High Definition Audio Bus" and an entry for NVIDIA HDMI Audio is missing, which is present in another PC that I have using this same exact mobo. I tried to reinstall the drivers from the manufacturer's driver disk, but the "Audio device on High Definition Audio Bus" still has the yellow marks, and the NVIDIA entry is still missing. So my questions are: 1) Is the motherboard defective? I still have audio coming out of the "line out" connector, which is the one that is connected to the 2 RCA plugs via a stereo plug to RCA adapter. 2) Does the HDMI cable carry audio and video, or just video? If just video, then maybe I haven't stumbled onto the correct settings yet to get the audio output. 3) If the mobo is defective as far as the "High Definition Audio Bus" is concerned, will a discrete sound card work? And if so, what kind would I need? Sorry for being long winded and jumping around topics. Any help and comments are welcome. Thanks. Mike