Screen savers were originally intended to prevent monitor burn-in, which could occur if a single image was displayed most of the time. Over time, that image would essentially become etched into the display, making the monitor harder to use. Monitor technology has improved over the years, and screen savers have become more a form of entertainment than a way to avoid burn-in.
Screen savers can be used to display your favorite photos or other images you'd like to see. Sometimes you might want to immediately start your screen saver like you would any other program, without waiting several minutes for it to start automatically.
To add a shortcut to your desktop that you can double-click to instantly start your screen saver
Click the Start button, and then click Search.
In the Search Results window, click All files and folders.
In the All or part of the file name box, type *.scr. Then, click Search.
You will see a list of screen savers in the search results. Pick the screen saver you want. You can preview it by double-clicking it. To add a shortcut to your desktop, right-click the file, click Send To, and then click Desktop.
Now you can instantly start your screen saver by double-clicking the icon on your desktop.