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 keyboard shortcut: Windows logo key + Shift + S.
Once Snipping Tool is open, make sure the screen content you wish to capture is visible. Your screen should darken 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!