How not to lose the Windowsx 10 key when reinstalling?

Question

Windows

There was a licensed 7 on the laptop, officially updated to 10. I want to somehow completely reinstall the 10-ku - for this I need to reset to the official 7ki? Is there a recovery partition on the disk, and then updated again, or can I somehow download the 10-ki image and use the 7-ki key?
And the second question. If I want to change the hard drive (to an SSD, so it's faster), can I officially put the top ten there somehow?

Answer 1

1) If you bought a laptop with pre-installed Windows, then the key is hardcoded in the BIOS (you can find out through RWEverything or AIDA)
2) Find out the version of Windows for which this key is suitable (for example, through Ultimate PID Checker)
3) Next, download the image of the 7-ki of the corresponding edition and upgrade to 10
4) After completing step 1, you can do whatever you want with the hardware