I guess it's funny, maybe not, but I have never owned a real version of windows. I did try once, and ended up with a technet version of win 7 for $20 or so. That was eventually busted, so I went with another corporate install, and then beat on that till MS accepted my version and ungraded me to win 10. It's a better games machine, there is no doubt. My ESO install, with about the same frame rate, was noticeably smoother.
I'm a happy camper, with my managed win 10, to run my games. I have not used windows seriously since NT 3.51, when I decided Linux would be more fun.