How to properly reinstall a system that was once pirated, but has now become licensed?

Question

Windows

There is a computer that has always worked under pirated Windows 7. Updates have always been disabled.
Already when Microsoft finished its imposition of Win10 (which never got in the way, because updates were disabled) and it seemed like the free upgrade to ten had already stopped, it was decided to take a chance and upgrade the computer to ten - what if it works out. They wrote on the Internet that the pirate seven can be upgraded to ten, but it will not be activated.
In short, in spite of everything - the end of the free update and the presence of pirates - Windows has successfully upgraded to an activated (!) licensed ten. My computer properties says "Windows activated" and below is the product key. At the same time, the newly minted top ten is regularly updated and still does not swear at its roots.
In short, a dozen took root, everything worked fine and is working. However, now there is a need to demolish everything nafig from the system disk and roll the OS in a new way (there are programs that you can’t just uproot just like that). Naturally, I want to keep the top ten. How to do it? With pirates, everything was simple - you format the disk, insert a CD or USB flash drive, and you're done. And what about this ten, without an installation disk / flash drive?

Answer 1

The method is described in detail on Geektimes . Most likely still working.