My wife has Windows 8.1 which installed itself last night without asking on her new ultrabook with Windows 8. It's a pretty unusable OS. The tiled front screen is full of spam with no obvious way to remove anything. No obvious way to shut it down. I gave up working out how to uninstall software. The new added Start button is a help but the whole UI experience is awful. Also Chrome is messed up out of the box, everything looks blurred compared to IE, but fixable through some options. They have a LONG way to go to make it run on a laptop. I can understand people upgrading to Windows 7, it will be a while before iterations make Win8 usable.