Are you perhaps going to reinstall Windows 10 and need to show the product key of windows 10?
It’s really easy.
Click on Windows start menu button.
Then type CMD and run it as a admin.
Then type the following commando into the CMD window:
wmic path softwarelicensingservice get OA3xOriginalProductKey
Now you should see the key right in that window.
I hope that this was helpful for some of you.