Windows for Pen Computing 1.0 is an add-on to Windows 3.11 with support for pen input. It ships with various pen tools, including a writing trainer, an on-screen keyboard, and a note pad. The Windows help has also been replaced with a Pen computing version. Windows for Pen Computing 1.0 was typically packaged with pen hardware sold at the time, and was also included with the Windows SDK.
Windows for Pen Computing 2.0 is an add-on to Windows 95 which adds pen input support. It has to be installed separately, and does not include any pen tools, unlike the previous version.