How to take a screenshot of a window and not the whole screen?

Question

On a normal system, I'd go AltPrtScr for a screenshot of only the current frame. According to the internet, the correct procedure for Surface 3 is to go FnWinSpace but that only takes a snap of the whole desktop.

I've tried adding Alt to the combination but got nada. I have no idea what else to test.

How can I do that on my Surface 3?

Answer 1

There is a difference in PrintScreen and Win+PrintScreen on normal Windows. The first copies the complete screen to the clipboard the second also saves it to your pictures-folder. The second only works on Windows 8 and higher.

So:
PrintScreen = Makes a screenshot and saves it to your clipboard
Alt+PrintScreen = Makes a screenshot of the current Window and saves it to your clipboard
Win+PrintScreen = Makes a screenshot and saves it to your pictures-folder
(There is no equivalent function to save the current window to your pictures-folder.)

With the Surface Pro 3 these function are reached via:
Fn+Spacebar = Makes a screenshot and saves it to your clipboard
Fn+Alt+Spacebar = Makes a screenshot of the current Window and saves it to your clipboard
Fn+Win+Spacebar = Makes a screenshot and saves it to your pictures-folder

(You can verify this by pasting in Word or Paint directly after using these functions.)

Edit (a bit off-topic because it's not native Windows but you asked for alternatives):
You could, as an alternative, use GreenShot. It has the ability to capture a window, a region and full screen with programmable function keys. It also has an editor and the ability to upload directly to imgur.com (which is really nice on sites like superuser.com).