 Microsoft 's work on handheld portable devices began with research projects in 1990 , with the work on Windows CE beginning in 1992 . Initially , the OS and the user interface were developed separately . With Windows CE being based on Windows 95 code and a separate team handing the user interface which was codenamed WinPad ( later Microsoft At Work for Handhelds ) . Windows 95 had strong pen support making porting easy ; with some saying " At this time , Windows 95 offers outstanding pen support . It is treating pens right for the first time . " WinPad was delayed due to price and performance issues , before being scrapped in early 1995 due to touchscreen driver problems relating to <unk> technology , made by NCR <unk> Products . Although WinPad was never released as a consumer product , Alpha builds were released showcasing many interface elements . During development of WinPad a separate team worked on a project called Pulsar ; designed to be a mobile communications version of WinPad , described as a " pager on Steroids " . This project was also canceled around the same time as WinPad . The two disbanded groups would form the Pegasus project in 1995 . Pegasus would work on the hardware side of the Windows CE OS , attempting to create a form factor similar to a PC @-@ esque PDA like WinPad , with communications functionality like Pulsar . A hardware reference guide was created and devices began shipping in 1996 , although most of these device bore little resemblance to the goal of a pen @-@ based touchscreen handheld device . 
