Alt + Print Screen Not Working

I have Windows 10 Pro on my laptop. After long time I am trying to capture screen by using Alt + Print Screen. When I click Alt + Print Screen and go into Paint or Word to paste it the Paste option is not working it remains grey, when I use Ctrl + V still nothing happens.

What can be the problem?
 
Solution
Since it works for me both on win 10 pro and home and on desktop and laptop... I would end up blaming one of the following:
1. for some reason keyboard doesn't like printscreen button. (this could be tested with separate usb/bluetooth keyboard)
2. Some anti-virus/anti malware/anti-keylogger software you have doesn't like screencaptures.

If neither of those help, I am out of ideas.
alt-print screen was scrapped.. no longer exists.
print screen button alone still captures whole desktop view.
microsoft prefers that people use their new snipping tool in windows 10

Edit: I said that since I had trouble with capturing only active window with alt-printscreen before but.. it seemingly works as I try it now. go figure.
Thus.. I have no real idea why it doesn't work for you. Might be tied to laptop special keyboard somehow failing at the key combination.
Possible other reasons might be virus scanners disliking screencaptures due their ability of snooping "sensetive data" or somesuch.
 
Since it works for me both on win 10 pro and home and on desktop and laptop... I would end up blaming one of the following:
1. for some reason keyboard doesn't like printscreen button. (this could be tested with separate usb/bluetooth keyboard)
2. Some anti-virus/anti malware/anti-keylogger software you have doesn't like screencaptures.

If neither of those help, I am out of ideas.
 
Solution

Ordered a keyboard will be arriving tomorrow. Let you know as soon I get it.