If you have an error message pop up on your screen, troubleshooting the issue is easier if you have the exact wording of the error. Taking a screen shot of the error will help technical support representatives get to the root of your problem. Screen shots also are useful if you want to keep a picture of a confirmation page when you purchase something online and don't want to print the page. The process for taking a screen shot is the same for nearly all versions of Mac OS on a MacBook.
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Have the content that you want as a screen shot centered on your screen. Press the "Command-Shift-“4.” The cursor becomes a crosshair.
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Move the cursor to the corner of the screen where you want the picture to start.
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Click and drag your mouse to select the content for the screen shot. A selection rectangle appears in the area you define. To adjust this rectangle keep holding down the mouse key as you proceed through the next steps.
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Move the selection rectangle as needed by pressing the space bar and moving the cursor. The rectangle follows this movement.
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Resize the rectangle around the selection center as needed by pressing the “Option” key and move the cursor. The rectangle resizes.
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Constrain the selection rectangle as needed by pressing the “Shift” key while letting go of the other keys. Moving the cursor horizontally constrains the vertical size and vice versa.
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Release all the keys, including the mouse. The screenshot will appear on the desktop with the name “Picture” and a number, such as “Picture 1.”
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Double-click on the screenshot so you can open and inspect it.
