If you need how to take a screenshot on windows for a single window, click the window you want, then press Alt + PrtScn. This copies only the active window to your clipboard. Paste it into an editor like Paint and save it.
To know how to take a screenshot on windows with a timer, open the Snipping Tool (or Snip & Sketch). Choose New, select Delay, set a timer, then capture the screen. The screenshot will open in the tool for editing and saving.
Win + Shift + S is the best way (Snipping Tool pops up and lets you select what you want). Win + PrtScn saves the full screen automatically, and PrtScn just copies it to your clipboard.
