To capture a screen shot on a Windows 8 machine do the following:
Windows Surface devices: Hold down the Windows key while pressing the volume-down button (both are the hardware buttons on the surface – sorry doing this on your keypad will not work). The screen captures get stored in the Photos app under “Screenshots”
Press “Windows” key + “Print Screen” (PrntScr). The screen shot gets stored under “Screenshots” in your picture library.