Windows 10: Why does it say activation key is wrong

I recently had issues on my computer so I brought it to microcenter. Microcenter stated they needed to do a a clean install and they said they would put a new windows 10 product key which I had to buy But in the settings it says my windows key is not input or setup and says "windows has reported that no product key was found on your device. Error code : 0xc004F213" I then tried to enter the key that came with microcenter and it does not work. What do I do?

:)

 

My PC suddenly says its not activated

For verification, now you are saying it isn't activated and Microsoft won't help you?

 

Windows 10 expiring activation problem

I have a pop up message appearing on the screen saying the licence will expire 15 August, need to activate Windows in Settings. Contact admin to get product key.
When I go to Settings it says Windows is activated and Product ID as well as Product Key is listed.
I have tried all suggestions from the Microsoft forum to no avail.
I am now wondering if the technician who installed Windows 10Pro, installed the wrong programme.
I believe that the previous Windows in the laptop was Windows 8.1 home.
Could this be the problem.
Any help appreciated. Thanks.

 

My PC suddenly says its not activated

So now I have a clean install and windows is activated, what are my steps to find out why my original windows install wasn’t activated......

I await instructions........

and apart from checking activation, I do everything else as per your suggestions......will in future check validated once a month.......