For Windows 8, click on the WinKey+PrtScn (windows key, usually to the left of Alt on the bottom left side of the spacebar) The screenshot will be saved in the Pictures/Screenshots folder.
in other versions of windows;
1) Press the PrtSc button on the keyboard. This is usually in the top right area of the keyboard.
Alternatively and preferrably you can get the active window screenshot by holding Alt then pressing the PrtSc button.
The Print Screen button can also be labelled as “PrtScn”, “Prnt Scrn”, “Print Scr”.
Once you take a screenshot, an image will be saved in the computers clipboard. AKA you copied the picture. Now it’s time to Paste it.
2) Open up PaintBrush. Click they WinKey then R (Winkey+R) or go to Start, Run and type in mspaint .
3) In PaintBrush, click on Ctrl-V or click on Paste from the top menu, or on older versions of Windows, Edit and Paste.
4) Click File and Save – you can save this picture as a JPG (or any other format).
now you have a Screenshot!
Capture theentire screen
Press Command (⌘)-Shift-3. The screenshot will be added onto the desktop.
Capture just some of your screen:
Press Command (⌘)-Shift-4, – drag the cross hair pointer to select the area. Then Hold Shift, Option, or the Space bar while you drag to resize the selection area. To cancel, press Escape (esc) before you release the mouse button.