It was quite a few years ago now since I worked at a Polish Tech Company who had already designed a PAD with Windows on it (was early 2000s).  It was always considered innovative by us but just a skunk RnD project.  After all it would never take off now would it – who wants to use a device like that we said –  Years later we have Tablets a go-go and here is a full review and worth looking at http://tablets-review.toptenreviews.com/