The USB Ethernet RNDIS (Remote Network Driver Interface Specification) driver is a device driver used to enable a USB-connected device (such as a smartphone, tablet, or other USB-based network adapter) to function as a network interface device on a Windows computer. Essentially, it allows the device to be recognized as an Ethernet adapter over a USB connection, allowing the computer to access the network through the connected device.

RNDIS is a Microsoft-defined protocol that allows USB devices to act like a network interface, such as a virtual Ethernet adapter. Commonly, RNDIS is used for connecting devices like smartphones in "tethering" mode (providing internet access from a phone to a computer over USB) or for USB-to-Ethernet adapters.