How to force Windows 7 to output 5.1 Surround?

OK, so unfortunately I ended up solving this problem like 6 hours after posting the bounty, so that was 50 rep wasted…

Anyways, it wasn't a software problem, or at least not on Windows's end.

Here's what I did:

1. Go to Sound --> Playback --> Realtek Digital Output --> Properties --> Supported Formats and select only Dolby Digital.

2. Select |> Test.
3. While Windows is sending the test signal, set the receiver to Auto Sound Digital mode, and the Listen Mode to Pro Logic.
4. After test completes, click Yes.

I can now listen to anything I want in 5.1 (ish - see below) surround.

The only issue is that the two rear speakers (the surrounds) are set to play the same signal, so it's really 4.1 surround (FrontR + FrontL + Center + Surround + Sub). This isn't too much of an issue, as it already sounds way awesomer.

I hope this helps someone else, and I'm willing to give the bounty away to somebody (post an answer to get put in the drawing - up votes to Question/Answer appreciated to help recover -50).

UPDATE:

It will play true 5.1 surround given a 5.1 source, like a DVD or other movie. But music seems to get 4.1, unless specifically written for 5.1.

And the bounty expired while I was out of town. So +50 really wasted.