The X550 Bus Enumerator is a device driver associated with Intel Ethernet Controllers, specifically the Intel X550 series of network adapters. The X550 series includes advanced network interface cards (NICs) that provide high-speed Ethernet connectivity for servers, workstations, and other systems. These controllers support various features like 10 Gigabit Ethernet (10GbE), Multi-Gigabit Ethernet (2.5GbE, 5GbE), and Virtualization Technology.

The X550 Bus Enumerator driver helps Windows manage these advanced network interfaces and ensures proper communication between the hardware (the X550 Ethernet card) and the operating system. It is commonly required when you are using Intel X550-based Ethernet adapters in a machine, either for high-speed networking or enterprise applications.