So I have recently purchased a used PC for a HTPC. It's a Dell Duo Core Quad with a 5770 graphics card. I freshly installed Windows, the Catalyst drivers for the card, VLC and Kodi. No sound works out of the desktop environment including VLC. When I load Kodi and play a DTS-HD encoded file, it plays the audio back fine (passthrough). When I play a DD 5.1 (AC3) it plays video and no audio (passthrough as well and tried no passthrough). My AVR decodes all of that so it isn't that. I also had my other PC connected and it worked fine. Any ideas?