Windows autoscroll makes this game too easy. This feature was introduced a very long time ago, possibly with the IntelliMouse in the year 1996. Press on the scroll wheel (considered to be middle-click) and release the button, which overlays a little scroll guide circle. Move the mouse down to begin scrolling, and don't touch anything else. Click any mouse button to stop scrolling. (Another variant is to click and hold the wheel button, move the mouse down to scroll, and release the button to stop.)