How to find your Windows 10 Product Key

I have been asked a lot of times by friends, family and people at work on how to find the Windows 10 key from their Machine. They want to re-use the key before they format their device or for any other reason. There are a few methods but below is my favourite one.

My favourite method:
Press Windows key + X
Click Command Prompt (Admin)
At the command prompt, type:
wmic path SoftwareLicensingService get OA3xOriginalProductKey

You will get below output: