If you like to take screenshots on Surface 4 or Surface Book:
Hold the power button down and then press the volume-down button to take a screenshot. The screenshot will be saved in the Screenshots folder under “This PC.”
you can also take a screenshot by just pressing the PrtScn by itself. It will be saved in the Screenshots folder of your Pictures library on OneDrive.
Take a screenshot by holding down the Windows key on your keyboard and pressing PrtScn
To take a screenshot of just the active window on your screen, hold down the Alt key and press PrtScn. The screen will be saved to OneDrive.
Double-click the top button of your Surface Pen to take a screenshot of your desktop. The full screenshot will be saved in your Screenshots folder on OneDrive, but this method also gives you the option to crop your image immediately.
For Surface 3 & Surface Pro 3:
There is a change in method one, Here you have to hold the Windows button and then press the volume-down button to take a screenshot. The screenshot will be saved in the Screenshots folder under “This PC.”
Rest of the methods are same.