The PenTablet Bus Enumerator is a Windows driver used to support pen-based input devices, such as digital pens, styluses, and graphics tablets, that rely on a PenTablet protocol. These devices are commonly used with tablets, touchscreens, and graphic design tools, allowing users to draw, write, and interact with the system more precisely than with a traditional mouse. The PenTablet Bus Enumerator ensures that these devices are recognized by the operating system and that the pen or stylus input is correctly processed.