Scrolling - Use one fingertip to slide up/down/left/right on the
touchpad to scroll a window up/down/left/right. If your display
window includes several sub-windows, move the pointer on that
pane before scrolling.
Two-finger zooming in/out - Moving two fingertips apart or
together on the touchpad to zoom in or zoom out. This is convenient
when viewing photos or reading documents.
Notebook PC User Manual