When you connect a WinUSB device, the system reads device information and loads Winusb.sys automatically.įor more information, see WinUSB Device. Such a device is called a WinUSB device and does not require you to write a custom INF file that references in-box Winusb.inf.

For certain Universal Serial Bus (USB) devices, such as devices that are accessed by only a single application, you can install WinUSB (Winusb.sys) in the device's kernel-mode stack as the USB device's function driver instead of implementing a driver.