Logitech z-906 5.1 surround speakers

[Evanescents]

So i got this speaker along with the new computer and when I try to test the speakers in the config, only the front left and front right is working even though I set it to be 5.1 surround. Then I go ahead and play so music on iTunes and it seem like the rest of the speakers are working... Any ideas?

 

[fireberd]

Have you set it as 5.1 in the Control Panel/Hardwre and Sound and finally the Sound Panel/Playback Section?
In the Playback section, click on the "Speakers" (your sound device) to highlight it and then click the Configure button. You can set the speaker type to 5.1 there and then test the speakers.

Also, make sure you have the speakers connected correctly to the PC (3 connections) and all the internal speaker connections are correct.