From Win98>Win2000>WinXP>Win7 it has been a slow but steady improvement in stability and features.. sure could have been better, but compared to Linux desktop distro's which none of them can barely even fucking match WinXp in terms desktop features and stability.. nvm the power shell extensions and eco system which don't exist. Because that only comes from good API's documentation and community that isn't completely stupid ... I would say that MS had a fairly good team of people up until the release of Win7, after that they seemed to have got a retarded shit for brains CEO Satyan noob tard, and replaced all the skilled people with fellow idiots.
And now Win10 is a stinking pile of broken and bug infested noob trash... it's built on the work that proceeded it, but they sure have done as much as possible to ruin that while doing fuck useful as an improvement in the underlying system let alone the UX/UI which hasn't improved at all its at best worse, they've just tacked on crap everywhere.