Windows 10: Upgraded Win 8.1 laptop to Win 10. If I do factpry reset will I need product key?

Upgraded Win 8.1 laptop to Win 10. If I do factory reset will I need product key?

:)

 

Win 10 Pro upgrade using Win 8 Pro product key

I just bought a new computer running Win 10 Home. When I went to upgrade to Win 10 Pro using my Win 8 Pro product key from my old computer, the upgrade wouldn't activate.

Now I'm stuck with a bunch of error messages (mainly 0xC004C003) and am being told windows isn't activated. I can't seem to get my activated Win 10 Home back.

I don't have a product key for the Win 10 Home because it came pre-installed. There's no product code recorded on the packaging or labelling on the device.

So:

How do I either

• activate the Win Pro upgrade, or
• Get my activated Win 10 home back?

 

Fresh Install of Win 10 without Serial Key?

Looking to reformat a laptops HDD, and then reinstall Win 10 fresh. The problem is it came pre-installed with Win 8 and I did the free upgrade to Win 10. How exactly would I re-format the HDD, reinstall Win 10 and ensure it reactivates properly? I don't see a Win 8 serial key anywhere in the contents of the box.

 

Win 10 Product Key

Hi,

I had a laptop with Win 8.

I then upgraded to Win 8.1.

Recently I upgraded to Win 10.

I also downloaded the Win 10 installation media.

But when I would do a clean install now, which product key do I have to use???