Just for the record (and because I tried all sorts of different search terms before finding this thread), the problem I was having was the 5.1 audio in W7 via HDMI stopped working. Device Manager showed the High Definition Audio device would not start (code 10). After reinstalling the Intel Graphics driver as suggested, the audio device now shows up as "Intel(R) Dislay Audio" and 5.1 works fine.
Thanks Again to the OP.
I have a question for you.
Does your Intel HDMI Audio device appear in the Windows 7 "Playback Device"?
Because i have installed "Intel (HD) Display Audio" driver sucessfull...but..since i can't see a "Playback Device" i can't set it as Default Audio Device in order to use it when i connect my HDMI Cable.
I tried more than 3 or 4 clean installs...with Windows 7 32-bit and Windows 7 64-bit.
I used Original Windows 7 professional SP1 discs for this, and also tried to disable windows update from the begining and just install the "Boot Camp Drivers".
But still no solution..
I also went to intel forums to ask with no solution yet.
And also tried Windows 8 Developer preview and Consumer preview.
My device is: "Apple Macbook Air mid-2011" and i also have Intel HD 3000 Graphics.
HDMI/Displayport Audio is working fine in Lion.
I just discovered a good clue on my problem.
I always use my A/V Receiver to connect HDMI devices.
I tried connecting directly my Samsung TV to the Macbook and Intel (HD) Graphics Audio recognized the TV and a new "Playback Device" appeared in the Windows menu.
So the currently problem is that (just in Windows 7, since in OS X HDMI audio is working with DENON A/V Receiver):
Intel HD 3000 graphics is not detecting <Denon A/V Receiver> as an "HDMI audio-capable device"
My denon A/V receiver ( DENON AVR-1712 ) is sucessfull detected by my netbook with Intel G45 Express Graphics, but not working if i use Intel HD 3000 graphics on my MBA.
Thank you so much for posting this fix! I had problems with my Macbook Air 2011 with something called "High Definition Audio Device" not starting properly. Since regular audio was working just fine, I just ignored it and blamed it on a boot camp quirk. It wasn't until I started using my MBA hooked up to a display through thunderbolt that I noticed that audio was not transmitting through the HDMI/Thunderbolt Cable.
It was maddening because I thought there was something wrong with my cable. I tried reinstalling the audio drivers from the bootcamp WindowsSupport folder (Realtek, cirrus, sigmatel, etc) but none of them worked. I did as you suggested and reinstalled the Intel video drivers and it worked immediately. Now I have audio and video through a single cable. Thanks a bunch dude.
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