I struggled with getting both audio and video through HDMI as well. I have a Sony VAIO VGN series connected to a brand new Sony 52" Z-series LCD and all I could get was video (looked great too!). I took the laptop upstairs and connected with a different
HDMI cable to 32" Panasonic LCD...same issue....great video but not audio.
I checked every W7 setting I knew and no luck. Got sound out of VGA + headphone ->audio jack but not via HDMI.
I searched the Internet for answers - nothing concrete.
Went to Intel to download driver update tool and it came back unsupported.
Called Sony and went through ____ with tech support. Finally was IM'ing with a Sony service agent who revealed that the HDMI audio drivers are included with the HDMI video drivers. I went to Sony's support site, entered my laptop in, searched on latest video
drivers and downloaded the newest drivers and VOILA! Worked awesome.
The misconception is that this is an audio driver vs. video. Hope this helps and feel free to contact me at *** Email address is removed for privacy *** for questions. I got pissed off for weeks about this problem so I'm happy to help.
Frankly I never suspected it could be a Windows issue or even the video player. I suspected it was something to do with the physical HDMI port and was told from one Sony agent that *some* laptops only support video from their HDMI ports. Never believed it.
Good luck all.
Lee