Jakob Nielsen says that Microsoft's new operating system is plagued by "hidden features [and] reduced discoverability," among other issues.User interface design guru Jakob Nielsen is none too pleased with what he's found in Windows 8, which he calls a "misguided" product.Nielsen, who has spent much of his career analyzing all kinds of user interfaces, including most notably Flash software for Web animation, says that the new Windows 8 user interface "smothers usability with big colorful tiles while hiding needed features."To arrive at that conclusion, Nielsen brought in 12 "experienced PC users" to try out Windows on both PCs and Surface RT tablets.