For
@billcorr, I want to thank you for showing
WHAT to get in Windows ; could I get a step-by-step run-down on HOW to use this procedure, for those of us who are Terminally Fumble-Fingered ??
I'd like to show why in '45, the importance of a Soviet port at Karachi is to the Jap navy !
I'm not billcorr but I like making step-by-step guides with screenshots

Assuming billcorr doesn't mind, please allow me to show you:
0. Step 0: Preparation
The following assume that you are composing a message in this forum's text editor, while also in the actual HOI 4 game that you want to show at the same time (you switch between the 2 by Alt-tabbing in Windows). Since the Windows Snip & Sketch tool stores its screenshot in the clipboard, its contents might be lost if not used immediately.
This procedure is not well suited to preparing screen captures ahead of time for use in a forum post later on, as they need to be saved in files first, and then uploaded. That is outside the scope of this guide. Personnally I prefer to use Steam screenshots that I then crop and edit in good ol' MS Paint before using them in a forum message.
1. Step 1: Press the Windows + Shift + S keys simultaneously on your keyboard to bring up the Snip & Sketch bar.
The Windows key is the key labelled with the ⊞ Windows
® logo, normally located between the Ctrl and Alt keys on your keyboard. It's easy to forget the key combination, so you may want to put up a Post-It note on your monitor... You can press Windows + Shift + S anywhere at any time, but for your scenario, you'd be in a HOI 4 game, and you'd have prepared your map to show the information you want to capture. In this case, the port of Karachi.
As shown in the following screenshot. You can see the Snip & Sketch bar at the top of the screen, and the prompt 'Draw a shape to create a screen snip' overprinted on the faded-out map (these effects are produced by the tool, they were not added by me in this undoctored screenshot).
2. Step 2: Draw a rectangle with your cursor around the part of the map you want to capture.
The rectangular selection tool is selected by default (it is highlighted in blue in the previous screenshot), so you can just go ahead and start clicking and dragging on the map with your mouse. You can cancel out of this step by pressing the Esc key (you'll need to start over from Step 1).
As shown in the following screenshot. You can see the area of the map that has been selected is back to normal intensity while the rest of the screen remains faded out.
3. Step 3: Paste into your forum message.
As soon as you release the mouse from Step 2, your rectangular selection is copied to the clipboard. Now press the Ctrl + V keys to paste the picture at the insertion point in the forum's message editor. As shown: