I installed in on a newish SSD drive that had Windows 8.1 on it and used the install via Windows Update route. All went ok although it took several restarts before Cortana began to operate. I realize it is in the formative stages, but to me it was very unimpressive. So far I see little reason to upgrade from 8.1 other than Cortana and, so far, she's dumber than my 2 ex-wives. And not nearly as much fun as they were at one time The UI needs a lot of work and I do mean LOT. One nice thing about the installation was they set it up with a dual boot like menu so when you start up you can choose to roll back to your previous OS. I think I will keep that drive dedicated to W10 though. It is easy enough to shut down and change drives and restart if I want to work with W10 for awhile. I didn't risk putting it on my Surface Pro I because I only have one of them. My desktop I can switch drives out quickly if things go awry. It may well be a better experience on a touch tablet than on a mouse / keyboard desktop. I'm waiting for new 4k touch screen monitors before I buy another monitor. So far you can get 4K or touch screen but not both --- but surely that will change soon. I hope. I can only hope that they pump out new updates VERY VERY often.