To capture an image of your screen, Windows 10 provides the 'Snipping Tool' application. The fastest way to find Snipping Tool is to use the Windows search function, located on your task bar.
Once Snipping Tool is open, make sure the screen content you wish to capture is visible and click 'New'. Your screen should lighten and your cursor will become a target. Click and drag over the content you wish to capture and when you release the mouse button Snipping Tool will have captured the area.
Click File > Save As, choose a save location and a name for your screenshot and click Save. All done!