The Matrox Millennium G550 is a graphics card that was released by Matrox in the early 2000s, designed for general computing tasks, 2D graphics, and video output. It was primarily used in workstations and in systems that needed stable, high-quality 2D graphics output, including for professional and multi-monitor setups.

The Windows driver for the Matrox Millennium G550 is software that allows the operating system to communicate with and utilize the hardware capabilities of the G550 graphics card. These drivers help manage things like display resolutions, color settings, and hardware acceleration for graphics tasks.