Sound surround wont work on X-530's

[Xplo]

Hi all just got a set of x-530's but when i play music sound only comes from the sub and two front speakers. Why not all of them?

Im thinking you can only get all of them going in 5.1 enabled games/movies? But is there anyway to get them going through windows media player? Any help GREATLY appreciated

 

[Xplo]

Well ive got onboard, do have a live card i could try though, thanks.