The Zoom Window tool magnifies a selectable area of the file to fit within the viewer window. Follow these steps to select an area to display:
Move the pointer to a location to indicate one corner of the area that you want to zoom.
Press the left mouse button and drag the pointer to the opposite corner of the desired area. A dotted rectangle will stretch from the first corner to the pointer, indicating the area being selected.
Release the mouse button at the desired opposite corner. The view zooms to the selected area.
You can also zoom in 50-percent increments using the + and - keys on the numeric keypad.