Licensing free Windows 10, did I lose my license after a clean install?

Question

Windows

Participated in the Windows 10 free license program.
The system was Windows 7 home (OEM), after updating and using it for a week, Windows 10 fell ill with errors. I completely demolished everything from the screws and installed Ubuntu, my wife is not happy ... Can I return the licensed Windows 10 with a clean installation? I read what you can, but:
1. What needs to be done to restore that license?
2. What version to download (does it matter)?
3. How will the activation be done?
4. Do I need an old Windows7 key?
I want to understand this process in order to be sure of the actions, thanks in advance.

Answer 1

When the seven was updated to the ten, did the ten activate normally? In the properties of the system it was shown that "activation completed"? Then no keys are needed. With a clean installation of dozens, you skip entering the key, the system will activate itself as soon as it gets to the Internet.

Answer 2

1. It was necessary to write down the key from Windows 10, which was issued during the upgrade (it is shown in the system properties). Don't forget to do this after you restore your system.
2. Most likely, you can install Windows 7 again and upgrade again. The key to the OEM version is usually pasted on the computer/laptop case. If there is a Recovery disk or partition (although I am almost sure that you have overwritten the partition), then you can restore Windows 7.
If not, you will have to search on torrents. You need to look for exactly your version (Windows 7 Home Starter/Basic...). The version on the sticker is also indicated.