Noted usability expert Jakob Nielsen has written about Windows 8 and its dual interface, drawing on the reactions of twelve users who tried Windows 8 PCs and Surface. Whatever your own take on Windows 8, it's an interesting read.
Where can you click? Everything looks flat, and in fact “Change PC settings” looks more like the label for the icon group than a clickable command. As a result, many users in our testing didn't click this command when they were trying to access one of the features it hides.
I wonder what Microsoft's own usability testing told it while Windows 8 was in the works?