Surround sound not outputing through pc.

[guitargod213]

So i was trying to hook up my old RCA RT2770 5.1 channel surround sound to my pc. Using the motherboards built in s/pdif port and the receivers it seems that only stereo is being output (with sub woofer). However with the test built into the windows settings it is output just fine. I opened up mw2 and selected 5.1 speaker setup (also tried windows default) and it was just stereo. Kind of bumming me out, but some insight would be nice. Do i need a sound card?
thanks

I should also say that the configure button is not able to be selected..

 

[guitargod213]

feel like a dumb ass.. apparently the audio drivers i had thought i downloaded, were never installed.

 

[firo40]

have you checked the "receiver" to see if its selected to output at 5.1, they have stereo option aswell which may be selected

 

[firo40]

Ahh that would be it then lol

 

[guitargod213]

Ahh that would be it then lol

yea haha i installed the driver, and now rocking out surround sound