Hello,i got a nvidia 8400gs hdmi awhile ago and when i go to control panel for sounds and audio devices it says there are none. i looked and the devices it came with a nvidia high definition audio thing but i don't no how to work anything to work if have been looking on the web but cant find anything please help!! + when my old graphics card was in there was sound.I re-downloaded Realtek High Definition Audio and installed it still nothing.