You might want to share a picture of something appearing on your computer's screen, also known as a screen capture, for numerous reasons, including the fact that screen captures can be a useful way to share lengthy error messages with computer technical support staff. Whatever your reason for needing one, the process of capturing an image of what's on your computer's screen does differ between Macintosh and PC computers.
Hold down the apple/command key (the key with an image of an apple or a small square with loops on all four corners) + the shift key + the number 4 key. A set of positioning cross-hairs, along with two sets of numbers, will appear once the third key in the combination is selected. The numbers reflect your cursors exact positioning in pixels, vertically and horizontally, on the screen. (If you would prefer to capture the entire screen, hold down the number 3 key instead of the number 4 key in the above combination.)
Position the cross-hairs at the top left side of the area, and then click and hold down the mouse button at that location.
Drag away from the initial cross-haired (top left) location, keeping the mouse button held, and pull down to form a box around the area you want to capture as a photo.
Release the mouse button after boxing in the desired area for capture. A camera click/shutter noise occurs at that moment.
Look for a new file on the desktop labeled Picture #.png, and open it in photo-editing software or in Mac's preview mode to edit or rename. If no previous photo has been taken, the file you are looking for will be named Picture 1.png.
PC Computer (Prior to the Vista Operating System)
Click the "Print Screen" button on the keyboard. There is no sound or visual cue presented upon clicking the "Print Screen" button, but an image of the full screen is now copied to the computer's clipboard. (To capture only the active window, hold down the "Alt" key + the "Print Screen" button.)
Open any program to paste the screen capture into (such as Microsoft Word, Paint or Adobe Photoshop).
Select "Paste" in your editing program to bring the photo into that program and crop or edit the photo as desired.
Choose "Save As," name the photo and save it to a memorable location on the computer.
Macintosh users: Select the number keys located directly above the alphabet keys. The numbers on the far right-hand side of the keyboard will not work for this activity.
PC users: The "Print Screen" button is sometimes labeled "PrtScn" when space is limited. PC users with the Vista operating system or later need to locate the Snipping Tool Utility under optional components and turn it on prior to attempting to capture an image of their screen.
If screen shots are being taken for more than technical support, and they contain text or images that were not self-created, make sure that permission is granted to use the information in the manner intended. Just because writing or photos are located on the Web does not mean they are public domain.