It is actually fairly simple. Go into the Logitech Mouse and Keyboard settings for the mouse. On the left side, 2nd selection down is an arrow w/ some lines next to it. When you click on it there will be the Pointer and Scrolling Settings. On the right side of that screen is a Scrolling Size dropdown menu where you can choose how many lines you want it to go down for each click of the wheel as well as if you want 'smooth scrolling'. It looks like you can choose between 1, 3, 6 lines or screen. Just make your choice, apply and try it to see what you like. I hope this helps. :)