If the thing shipped with 7 or 10, it is not necessary to extract the product key. It’s in the system’s firmware and Windows will recognize it.
Is there some reason you don’t want to do a fresh install of 10?
Also, the N22 is a slightly glorified ChromeBook - in fact, they sell a version of it as a ChromeBook. It’s not great; personally I’d replace it with something else.
The N22 shipped with Win 7 Pro and I updated it to Win 10 Pro during the free upgrade to 10 period.
The main reason I didn’t want to reinstall the OS is the work that goes with that to get everything re-customized to my preferences. But then again, at this point, that may be a smaller factor. There’s also a familiarity factor in that I don’t know how to force the reinstall to the M.2 drive instead of the eMMC (which latter I doubt will do me any good.) And if I DO move the OS to the M.2 drive this way, then I have to reinstall my non-MS programs — although in THIS particular case that is not a big problem as I do not have a lot of programs on this machine anyway, most that are were running from the SD card / slot, and I’d want to reinstall them to the SSD anyway...
Somewhat agreed about the N22, although it certainly proved a better machine (in use and reliability) than my previous ASUS T100TA. Arguably, since I’m very happy so far with my Dell Latitude 5490, perhaps I should just look for a smaller version of it. (These “netbooks” are mostly for when I need to “travel light”, or, at least somewhat more “compact”.)
FWIW, I would not be surprised if Lenovo did not sell more of the Chromebook version of the N22 than the Windows version. A lot of primary schools use the Chromebook version in classes (including the classes at the small church school my wife teaches at.)
My biggest gripe about the N22 is that I never really adapted well to its keyboard, while the Dell 5490 is wonderful in that regard, for me.