On a Mac

1. Press Command + Shift +4. Your cursor will turn into a small cross-hair icon. 

1. Click and drag your cursor to highlight the area you'd like to take a picture. A grayed rectangle should appear where you drag your cursor. If you need to adjust your windows at all, press Escape to return to a regular cursor without taking a picture.
   
   
   
   
2. Let go of the mouse. You should hear a brief camera shutter noise if your computer's sound is turned on. That signals that your screenshot has been taken.
   
   
3. The screenshot will be on your Desktop saved as a .png file named "screenshot" labeled with the date and time. Rename as necessary.
   
   

On a PC

1. Click the Start button. Type Snipping Tool in the search box and click Snipping Tool to open the program.
   
   
2. Click the arrow next to the New button and select Rectangular Snip.
   
   
   
3. Select the area of your screen that you want to capture.
   
   
4. To save the capture, click File then Save As. Choose a location and name the file. Click Save. (NOTE: JPEG is the most common format.)

Using a Keyboard Shortcut on a PC 

1. Press Windows Logo Key + Shift + S. The screen will gray out and you'll see four options at the top of the monitor to select from for your screen capture: Rectangular, Freeform, Window, and Full Screen.
   
   

1. The image will be captured in your Clipboard.
   
   
2. Press CTRL + V to paste it to a destination.