A "screenshot" is a snapshot of all what's on your computer's screen.

To create a screenshot follow these steps:
  1. The first step is to create the windows that you want to capture and leave them up on the screen.
  2. Just to the right of your keyboard, if it is a standard one, you should see three groups of keys. The lower set of keys usually is a group of arrow keys. Above that is usually a set of some six keys that are labeled "Insert," "Home," "Page Up," etc. Above that should be three keys that have rather odd labels - like Pause/Break and ScrLk. One of those keys should be labeled PrtScrn/SysRq. Pressing Alt-PrintScreen (Alt-PrtScrn) places an image of the frontmost window on the clipboard. Pressing PrintScreen by itself places an image of the entire desktop on the clipboard.
  3. If you press PrtScrn/SysRq, nothing will appear to have happened. However, your computer just took a snapshot of its screen and stored that picture on its clipboard, much as it stores information that you cut and paste.
  4. Open MS-Paint. (From Start/Run, issue the command "mspaint".) Create a new empty image, and use Edit/Paste to bring in the screenshot you just took. (If the screenshot is smaller than the default Paint canvas, you will end up with white areas. Start over: create a new empty image, change its dimensions to 1x1, and Paste again. The canvas will grow for the Paste, but it doesn't shrink. Another way to do it is to click the lower-right corner of the canvas (there’s a little black square) and adjust the size of the canvas manually.)
  5. Use MS-Paint to Save As, using PNG or JPG as the file format (it is superior to all the rest).
Thanks to James Blond for translating this piece of FAQ.