Once upon a time there was Windows CE which served as the underpinnings for what became Pocket PC and then eventually Windows Mobile. Microsoft created Windows Mobile Professional for smartphones with touchscreens, Windows Mobile Standard for phones without touchscreens, and Windows Mobile Classic for personal digital assistants of Pocket PCs back in the day. Microsoft’s more modern Windows Phone 7 operating system originally debuted as Windows Phone 7 Series, before the company quickly realized its mistake. Windows Phone has held strong for nearly four years without any Professional, Classic, or Standard versions.
