The 3Com 3C920B-EMB Integrated Fast Ethernet Controller is a network interface card (NIC) integrated into many motherboards or as part of a system's chipset, providing Fast Ethernet connectivity (10/100 Mbps). It's commonly found in older systems, as 3Com was a major manufacturer of network hardware before being acquired by HP in the early 2000s.

The Windows driver for the 3Com 3C920B-EMB Integrated Fast Ethernet Controller allows your operating system to communicate with the hardware, enabling network connectivity for your system. Without the correct driver, Windows will not be able to recognize the NIC and establish network connections.