If a window is too small to display all its contents, scroll bars appear. A scroll bar is a vertical or horizontal bar at the side or bottom of a window that you can move with the mouse to slide that window's contents around.

A scroll bar has three components: scroll arrows at its ends for moving incrementally, a sliding scroll box for moving to an arbitrary location, and the scroll-bar shaft (gray background) for jumping by one windowful at a time (Figure 1.41).

To scroll a window's contents:

• To scroll up or down line by line, click the up or down scroll arrow.
  or
  To scroll up or down incrementally, press an arrow key.
  or
  To scroll up or down by a windowful, click the shaft above or below the vertical scroll box, or press Page Up or Page Down.
  or
  To scroll left or right incrementally, click the left or right scroll arrow.
  or
  To scroll left or right by a windowful, click the shaft to the left or right of the horizontal scroll box.
  or
  To move to an arbitrary location, drag a scroll box to the place you want. (Some programs show the scrolling content or a location indicator while you drag so you know when to stop; other programs make you guess.)

Tips

• If your mouse has a wheel, you can scroll up or down by turning it.
• In many programs you can press Ctrl+Home and Ctrl+End to go to a document's beginning or end. If yours won't, the fastest way to scroll is to drag the scroll box to the top or bottom of the scroll bar.
• In Windows Explorer, Internet Explorer, Notepad, and some other programs, you can right-click anywhere on a scroll bar to show a navigation shortcut menu (Figure 1.42).
• Holding down the mouse button on a scroll arrow or shaft autorepeats the scrolling behavior. (If you lean on the shaft for more than a few seconds, Windows can lose track of video memory, and the window contents will appear distorted or sliced up before Windows recovers.)
• You can use the mysterious Scroll Lock key for keyboard scrolling. When Scroll Lock is toggled on (its keyboard indicator is lit) and you press a navigation key, some programs scroll the view without affecting the cursor or selection.

Figure 1.41 The size of a scroll box is proportional to the fraction of the window contents displayed, so the scroll box indicates visually how much you can't see, as well as showing you where you are.