How to force Win to use AMD HDMI Sound Drivers

For whatever reason, in Win 7 64 bit, my AMD Radeon HD7770 HDMI shows as "High Definition Audio Device" (the generic Microsoft drivers) rather than "AMD High Definition Audio Device". I have the same hardware and drivers on a dual boot (separate hard drives) on Win 8 and it shows as "AMD High Definition Audio Device".

Things I've tried:
1. Uninstall the High Defintion Audio Device in the Device Manager then restart the PC and let Windows detect and reinstall. Did not change.
2. Search for new driver, but all it finds is the one that is already installed.
3 Uninstall the HD Audio Device in the Device Manager again. Then install the latest AMD Catalyst/driver (the beta version, as I had the latest non-beta version installed), restart the PC. Still have the Microsoft driver listed rather than AMD.

Which driver works better is not the point. It should be using the AMD driver, not the generic Microsoft HD Audio Codec driver. My on-board audio (RealTek) is using the RealTek driver.

Fixed. Fell back to the 12-10 Catalyst/drivers. That was the one thing I didn't try. With the 12-10 drivers it shows "AMD" in the HDMI.

The 13-1 and the 13-2Beta5 when installed both show HD Audio (Microsoft). Must be a bug in the Win 7 drivers since the same drivers in Win 8 have the correct AMD in the HDMI.

I wouldn't think RealTek would have anything to do with AMD Radeon HDMI. ????

That is an old driver, older than the one I got from AMD.

Also, note:

Audio drivers available for download from the Realtek website are general drivers for our audio ICs, and may not offer the customizations made by your system/motherboard manufacturer. To be sure you obtain the full features/customizations provided in your original audio product, please download the latest drivers from your system/motherboard manufacturer's website.