What is an MCI file? An MCI file is a configuration file used by the Media Control Interface (MCI), a system introduced in Microsoft Windows 3.1 that helps control multimedia hardware and software. It contains information that provides a command-based interface for allowing programs to control media devices, such as CD players, MIDI instruments, and video playback systems, without needing to interact directly with each device’s drivers.

More Information Microsoft introduced MCI in 1992 as part of its efforts to standardize multimedia support across Windows. It allowed developers to issue simple text commands (like play , pause , and stop ) to control media. MCI remained widely used through the Windows 95, 98, and early 2000s era, particularly in consumer and educational software that needed basic audio and video playback. However, MCI is rarely used now, making MCI files obscure.