How do get my mouse wheel to scroll differently?

All of a sudden today my mouse wheel is scrolling from the top of the page to the bottom in just one scroll of the click wheel. I remember seeing somewhere that I could adjust how much area is covered in scrolling but can’t find it now. I did find where to adjust how fast it scrolls but that isn’t what I had found before. Can anyone help me? I am running Windows 7 if that makes any difference. I have looked at all the properties on the device… I’m stumped.