I have this PC (P5EVM-DO) with a AMD RADEON HD 6350 video card + a dvi to hdmi converter and a hdmi cable going in a big LG screen (42PQ30-UA) on windows 7 64-bit
In the Playback Devices menu with all hidden options checked I only see Speakers (which works) and Realtek Digital Output (which does not play sound)
But on most videos on youtube, people have a screen icon with hdmi sound options, and I don't.
I have tried uninstalling the realtek sound drivers, and amd video drivers, trying installing them each separately, but i get no hdmi options. Any help?Does the card support audio via DMI ? ?

All of them do not.good questionMany times it won't work with cheapo adapter ALSO...i have another computer at my other appartement and used the same adapter, no sound problem.
I also tried a male male cable on the stereo jack behind my pc that works with my speakers into the audio in hole behind the tv and not MUCH success eitherDVI doesn't officially carry sound, however some video cards support it to allow people to use adapters on machines where a regular HDMI port wouldn't fit.  I imagine the PC that the adapter works on SUPPORTS this but the one it doesn't work on doesn't support audio over the DVI port.

As far as the audio input port on the TV, you'll need to check what input this feeds audio to, on one of my TVs it only works when the TV is getting video over the VGA port.