The Analog Devices MPU-401 Plug and Play Windows driver is a software package that allows your computer's operating system (OS) to communicate with the MPU-401 MIDI (Musical Instrument Digital Interface) interface, which is often used for connecting musical instruments, synthesizers, and other MIDI devices to a computer. The MPU-401 itself is a MIDI processing unit, and its Plug and Play (PnP) driver ensures that the device is automatically recognized by the operating system without requiring manual configuration or special settings.

This driver is commonly used in older systems (though still functional in some legacy setups), especially when using soundcards or MIDI interfaces that rely on the MPU-401 standard.