I’m not a Windows user and I know this is not a popular opinion, but… I really wish Windows 8 had been better received. Sure it was a huge break from Win<8. But it was a bold, thoughtful and thorough one, with a lot of potential. Refining Metro but ultimately sticking to its core ideas would almost certainly have produced a better Windows experience overall than the basically incoherent changes which followed.
What I don't understand is why they decided to shoehorn Windows onto their tablets instead of the Windows Phone OS. Windows phone was well received, it would have made far more sense. Apple could see that wasn't going to work, why couldn't Microsoft.