- To take a screenshot of the entire screen click the prtscrn (print screen) button on keyboard.
- Alternately to take a screenshot of just the active window hold the alt key and hit the prtscrn key.
- You'll now have a copy of this on the clipboard, open any image editing program and you can paste the image into it. For example Paint
From there is options like cropping and what you're going to save it as,. Generally speaking I'd suggest .gif for screenshots with any tool except Paint. Save as .jpg instead with paint.