Of course, they needed a software program to run the thing so in 2002, they launched the Windows XP Tablet PC edition and upgraded the version in 2005. Early models of tablet PCs that used their software were Acer Travelmate C100, Toshiba Protégé 3500 and Fujitsu Stylistic ST4000. However, much to the dismay of Microsoft, the response of the market was lukewarm. A few reasons for this was the battery life so you needed an iPad charging station or something similar to it. Another thing was that the applications were not adapted to the slate format and the most common reason was that the units were just too heavy and could cause some strain in the user when used for a long period.