The NVIDIA nForce PCI System Management (SMBUS) driver is part of the set of drivers provided by NVIDIA for its nForce chipset series, which was commonly used in motherboards for PCs. The SMBus (System Management Bus) is a communication protocol used to manage and monitor system components like temperature sensors, fans, and voltage regulators.

This specific driver allows the operating system to interact with the SMBus and ensure proper communication with hardware components, including power management features. It's especially relevant for systems running on NVIDIA nForce chipsets, which often include integrated components like Ethernet, audio, and SMBus.