Device instance ID

A device instance ID is a system-supplied device identification string that uniquely identifies a device in the system. The Plug and Play (PnP) manager assigns a device instance ID to each device node (devnode) in a system's device tree.

The creation of the device instance ID for a device uses the bus driver reported device ID value, instance ID value, and the UniqueID member of the DEVICE_CAPABILITIES structure as input in order to create the unique device instance ID for this device on the system.

The number of characters of a device instance ID, excluding a NULL-terminator, must be less than MAX_DEVICE_ID_LEN. A device instance ID is persistent across system restarts.

The following is an example of an instance ID ("1&08") concatenated to a device ID for a PCI device: