That does ring a bell but I don't _think_ Win98 accepted Win3.11 floppies as valid media (or at least did not accept mine, which I am not sure were 'originals')

That does ring a bell but I don't _think_ Win98 accepted Win3.11 floppies as valid media (or at least did not accept mine, which I am not sure were 'originals') and my Win95 disc was also an upgrade version. I do remember playing similar shenanigans just a couple of years ago when I bought a laptop without Windows and I did not know that the Windows licence that came with my old laptop was bound to that machine... I had a random Windows 8 key lying around and through a bit of wrestling (which I should have probably documented...) I was able to use that to install a new copy of Win10 on my laptop (which should be upgradable to Win11).