I'm working from memory here, but I think if you open the soundcard properties (by double clicking onthe little yellow speaker icon in the bottom left corner of your desktop), then find the properties option in the first drop-down menu (I forget what it's called) it should bring up a dialogue box where on of the options is "advanced options". If you click this checkbox, then exit the properties window, a little box saying "advanced properties" should appear on the volume control. Clicking this will bring up faders for treble and bass (I think) and you should be able to turn both off here. I'll have play tonight and see if I'm right!