The ability to see photos in full-screen mode on the computer cuts down background distraction from icons cluttering the desktop. In Windows, when you open a photo in Windows Explorer, press the F11 key on the keyboard to expand the picture to the full screen. If it does not work, the manufacturer may have modified the keyboard function; try pressing the Function key and F11 or check the computer's manual.
Pressing F11 when looking at a photo or video in Windows Media Player should also expand it to a full-screen view. The F11 key expands windows to the full screen as well. Press the Escape key to close the full-screen view.
In Mac OS X 10.7 and 10.8, you can click the arrows in the top right c orner of a photo in the Mac's built-in Preview program to expand it to the full screen. With the Quick Look function on the Mac, however, you do not even need to have the photo open in the Preview program - just click on the photo's icon and press the Mac's Option key and Space bar to see the image expand to the entire screen; the Quick Look shortcut also works in Mac OS X 10.6. Press the Escape key to return to the normal view.