Windows 10: need a product key of this PC

I need to activate my windows 10 to genuine, I need a product key on this PC

:)

 

Product key association disable on old pc

Hey,


I sold my old pc to a friend. He installed some missing parts (HDD, GPU and RAM). Then we installed Windows 10 Home 64-bit version from USB stick. I was surprised to see that windows was automatically activated after that. I did some digging and found out that it is using my product key, which i use now in my own new pc. My friend does not have his own product key, the idea was that he just uses the unactivated windows with limited features.


I uninstalled my Windows 10 product key via command prompt in friends computer (as i understand this is only local solution, if he reinstall windows or clicks the active button, it reactivates automatically with my product key) and now it says windows is not activated, but my product key is still shown with Produkey app in his pc. So far windows is still activated my own pc.


My questions:

1. Is this all i need to do?
2. How do i get rid of product key showing still with product key showing apps on my friend's computer?
3. Is there a way to get rid of association of my product key on that old pc that i sold to friend?

EDIT: I originally installed windows 10 via upgrade option from Windows 7, if that matters.

 

Why was I not asked for a product key when upgrading to Win 10?

According to your spec you have Win 10 Pro, but perhaps that doesn't reflect your PC.

You haven't stated which edition of Win 10 you have on this machine, nor what your Win 10 key is for.

For example, if you already have Win 10 Pro and your key is Win 10 Home, that would be a retrograde step.

For interest only:
Change Product Key in Windows 10

More on product key if you search this list or look at 'Related Tutorials' in the above.
Windows 10 Tutorial Index

 

Where is my Product Key if I want to re-install?


Like davidhk said. But if you really want to see your windows key, I would suggest Belarc advisor. It will give you some useful information about your system, product keys of your software is among them (not only Microsoft, you will have listed most of your keys).