Speaker fader controls-where in Vista?

Intel D865PERL m/board with integrated SoundMax 5.1 audio.

Where do I find the left/right, front/back, center, sub volume controls in
Vista?

I could set up the speakers for 5.1 by right click on volume control in task
bar > Sounds > Playback tab > click on Speakers and click configure. I could
set for 5.1 and tested all ok (sound coming from all speakers).

When I go into Windows Media Player, I only get sound from the front 2
speakers. Help??