this should probably be in hardware vercetti.

So as I see it....you do get sound out of your speakers if you plug them into the CD headphone jack - thus the problem isn't your speakers. What about your soundcard - all drivers up to date? I take it you have checked the usual volume controls in windows as well as on the speakers themselves? What soundcard are you using? What kind of setup is it stereo, 4.1, 5.1??

a little more info would help

Z