After a fresh start with a clean install of Windows 10, will I need to activate Windows?

Question

Windows

I currently have Windows 10 Home Version 1607. I have it with a license. When I bought it, it was Windows 8, then after the update it costs Windows 10 Home Version 1607. It started working slowly for me, I decided to restore the factory image of the computer. If I restore to a factory image, will my windows 10 license key be lost? Or does it automatically activate my Windows? Who hasn't experienced this? Or will I have to buy a new key? I just don't want a pirated one with an activator, I want it to work with the original Windows key.
I tried this method but after the update it no longer works because my version is 1607!
Go to Settings > Update & Security > Recovery > Reset this PC > Getting Started and select Factory Reset.
There is an option, but I don’t know after that my Windows with the key will work, who did it?
https://www.microsoft.com/en-us/software-download/...
What could be done? What are the options?

Answer 1

If you upgraded from 8 to 10, then your old key will now be suitable for 10. Everything should be activated automatically. In case of problems, the first step is to try to activate via the Internet with the old key, if it doesn't work, activate by phone with the old key. Downgrading shouldn't be a problem either, if the need arises.

Answer 2

If you have activated Windows 10 at least once and you have a Microsoft account, then the very concept of a "key" is no longer relevant for you.
When you reinstall the system on the same computer and sign in using an existing Microsoft account, the system will be activated automatically.