Windows 7: Radeon HD 5750 no HDMI sound

It's funny that it would stop working the day I had plans with friends to play Amnesia: The Dark Descent all night. Oh, well, though.

So, here's the problem: I installed the card, and initially had no sound. After browsing the forums here, I came across the a very useful thread here. I followed all the steps that were suggested here - I upgraded my ATI Catalyst, made sure the HDMI sound driver was installed, and even tried the Realtek driver suggested on page 2. That one finally worked! This morning when I turned my computer on, everything was fine and dandy until I installed a couple updates from Windows Update, and then upon reboot, there was no sound.



None of the updates had anything to do with audio drivers. They were the malicious software removal tool, an ethernet update from athros, and an update for windows x64 systems. After having no sound, I retried all the steps, but this time to no avail.

System Specs
Windows 7 Ultimate x64
ASUS M4A78T-E motherboard
Phenom II x4 955 Black Processor
Radeon HD 5750 GPU
4GB G. Skill RAM
320 GB Western Digital HDD

***EDIT: Apparently, the Update for Windows x64 (KB976422) disabled my sound driver***

Some of the Windows updates corrupt various things. I assume reinstalling the sound driver fixed your problems.

I ran into a problem with Sonar (my recording studio software) that all of a sudden I was getting an error message to reinstall Sonar. I reinstalled and that did not fix it. On a whim I tried starting it as Administrator and it started OK, no errors. As it turned out one of the Windows updates did something to the C:\Program Data folder and just accessing the folder (it required authorization) fixed the Sonar program problem.

No, it didn't. I had to uninstall the update, which was for compatibility with SD cards (for which I don't have a slot, anyway). Though it is curious that an SD compatibility update would mess with sound drivers.