Or, use the MS snipping tool with the keys: widows key,shift key, s key.
The screen will dim. Select the portion you want to capture with the mouse, left mouse key down. When the left mouse key is released the selected area is captured.
At the lower right you will briefly have the option to open a mark up screen where you can write/and or point to something on the screen capture, else it goes to the desktop.
In the markup window, if you select it, you have the option to store the capture where you want it.
The captured file name is timestamped in jpg format.