Thanks for this post. I have a Asrock Z68 motherboard.
I use the .bat file method.
One thing I did was launch a cmd-window (in Administrator mode) so I could see the results of the .bat calls, in case anything went bad.
I was able to get Dolby Digital Live to work with my Sony STR-DG500.
Note that I had to Right Click the "Realtek Digital Output" (and click Properties) and go to the "Supported Formats" tab (where the tabs are General, Supported Formats, Levels, Enhancements, Advanced).
On the "Supported Formats" tab, I did tests for "Encoded formats" and "Sample Rates". What worked for ~~my~~ sony receiver was "Dolby Digital" and "48.0 kHz" and "96.0 kHz". Your mileage may vary.
My steps were to install the drivers, run the first .bat file (the "start" one), make the changes to enable "Dolby Digital Live" in the realtek program, close the realtek program, run the second .bat file (the "stop" one), and then run the tests from "Supported Formats" tab.
What I was missing is that you cannot run the tests from the real-tek program, because when you put back the original .DLL, those options are disabled. So by using the "Supported Formats" tab, I was able to do some basic testing.
Also note that when I got sound to work from the "supported formats" tab, only my front-left, center, and front-right speaker worked ~~during~~ the test. However, once I got sound from those 3 speakers, I tested using some of the 5.1 files from this site:
http://www.diatonis.com/surround_sound_music.html
So I get the flow now. Use the mod dll to make changes to settings, put the original back so it runs, and the original won't through the non-signed (puma) error. If I make changes in the future, I'll temporarily put back the modded dll, make the changes, put back the original dll.
THANKS to the OP and everyone where who posted hints and tips.