Sometime you can get fake surround thru your amp by enabling pro logic or other similar modes.
Windows has a problem where it can only pass thru a 5.1 vai an ac3 audio stream or else you only get 2 channel audio via s/pdif. But if the audio stream isn't ac3 no 5.1.
So if you do hook it up you will only get surround if you properly configured ur pc to pass thru 5.1 to your amp to do the decoding or as i have done bought a high end sound card that is capable of upmixing all audio to DTS digital.
So that way if I play games/movie its in full 5.1 thru my sony amp.