I have Altec Lansing VS3251 5.1 channel speaker attached to my computer, now initially when i got it they all were working good even on 2 channel track, all of them gave out sounds. Now after installing window's only front 2 give output, the rear don't make any sound. I have checked the driver, did setting to 5.1 channel under audio config in computer, re-checked the wires to make sure they are where they belong, but still there is no sound from rear 2 + 1.
Please share what you know over this, its been 3 months and i did what i could, i am not much of expert in speakers.