The document discusses the evolution of the user interface design for Microsoft Windows CE. It describes three iterations: the Handheld PC from 1995 which resembled a desktop PC but had usability issues; the Palm PC from 1998 which had a smaller screen and alternative inputs like handwriting but data entry was still difficult; and the Auto PC from 1998 which was designed for in-car use without a touchscreen or stylus and emphasized voice commands. While Windows CE aimed for consistency with desktop Windows, usability tests revealed issues at each stage and consistency alone did not guarantee success.