Screen savers can help protect your monitor from wear by showing a constantly changing display when your computer is not being used.
Right-click your desktop, and then click Properties.
In the Display Properties dialog box, click the Screen Saver tab.
Click the Screen saver drop-down box, and then click a screen saver.
Click the Preview button to see how the screen saver will appear on your monitor.
Move your mouse or press a key to return to the Display Properties dialog box. To try a different screen saver, return to step 3.
Click the Settings button to change the standard behavior of the screen saver you selected. (Each screen saver has its own settings dialog box.) Then, click OK.
In the Wait box, type the number of minutes the computer should wait to start the screen saver after you last touched the keyboard or mouse.
If you are the only person who uses your computer and you are not concerned about security, clear the On resume, display Welcome screen check box. Otherwise, leave this check box selected.
Windows XP will start the screen saver you selected after your computer has been idle for the specified number of minutes. You can also
instantly activate your screen saver. To stop the screen saver, just move your mouse or press a key.