I really don't know much more than the control panel options for configuring audio on my PC, so forgive me. I am using Vista Ultimate x64, and my motherboard is using AC97. The only time I can get Dolby Digital 5.1 output is when I'm using Media Center and watching HDTV. However, whenever I play music files (in any program) or watch Blu-Rays in PowerDVD, I cannot get Dolby Digital output. Everything is stuck at the standard 2 speaker output. I have updated to the latest Realtek AC97 drivers for my motherboard and tried using AC3 Filter audio codec, but I can't make too much sense of it. Should I just give up and get a sound card? I'm concerned because I'm not sure why I can't get 5.1 DD with the current config.