PC to Receiver via HDMI only plays 2 Front+Sub and not 2 Surrounds

[fadedxxx]

So I have a VSX 1123k setup with 2 front speakers, a sub, and 2 speakers plugged into Surround L/R, and my computer goes into the receiver via HDMI. That HDMI audio output has been configured in Windows7 to 2 diff 5.1 settings, and a 7.1 setting, but I still always only get audio out of the 2 front+sub only i 99% of the audio settings. I can get all of the speakers to work when I do ext. stereo. However, when I choose ext. stereo the 2front+sub audio quality drops significantly than when sound is coming from them via the Pure Direct setting on the receiver. Almost significantly enough that I'd rather run 2 speakers in Direct than all 4 in ext. stereo.
Is there something I can do to get the audio to play on all the speakers in Pure Direct? I honestly don't care about the "surround" since I'm mainly using it for music.

 

[americanaudiophile]

You could connect the front speakers to the speaker A position and the rears to speaker B. Leave the sub connected to the sub output. Setup the receiver for a 2.1 channel system and the PC to a stereo 2.0 configuration. Now you can use any pair of speakers alone or together. I think you will find more speakers aren't usually better just more sound.
I don't know if the Pure Direct Mode will turn off the sub so you will have to try it.
Since you are trying to get the best fidelity on music you should consider using a digital output from the PC to feed the receiver. That way you are using the digital to analog converters in the receiver. If your PC doesn't have digital out then you can add a sound card that does or a USB adapter for this
http/www.amazon.com/PCM2704-Optical-Coaxial-Decoder-Converter/dp/B0093KZTEA/ref=pd_sim_sbs_e_5?ie=UTF8&refRID=01VG42Q5EBT50CAEHRE8
Another way is to load your music on a USB drive and plug that into the receiver.