1. Press the “Print Screen” button on your keyboard.

   2. Press ctrl+c

   3. Open Microsoft Paint. To open Paint, open the Start menu,

    4. Press ctrl+v / paste

    5. Save the screenshot. Click on File, then select “Save As…”

                           SNIPPING TOOL METHOD 

    1. Open the Snipping Tool. Open Snipping Tool by clicking the Start button , clicking All Programs, clicking Accessories, and then clicking Snipping Tool Or type in the search box Snipping Tool.

     2. Choose the kind of screenshot (snip) you would like to take. “Rectangular Snip” is chosen by default.

• “Free-form Snip” lets you draw an area of any shape. Only the area you drew will be snipped.
• “Rectangular Snip” lets you select a rectangular area, which will be snipped.
• “Window Snip” lets you choose a window to snip.
• “Full-screen Snip” snips the whole screen, with all windows (except the Snipping Tool window) included.

     3. Select the area that you want a screenshot of. If you chose “Window Snip”, select a window instead. If you chose “Full-Screen Snip”, go to the next step.

   3. Save the screenshot by clicking the floppy disk icon in the window that pops up. Type in a name for the screenshot and change the “Save as type:” field if desired.

Snipping Tool is an application included in Windows 7, Windows Vista, and Experience Pack for Windows XP Tablet PC Edition 2005.

Note:

When Snipping Tool is open, a white overlay appears on your screen until you capture a snip. To turn off the overlay, open Snipping Tool, and then click Options. In the Snipping Tool Options dialog box, clear the Show screen overlay when Snipping Tool is active check box, and then clickOK.

(credits: wikihow)