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Device Instance ID

Last Updated: 4/22/2017

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 format of this string consists of an instance ID concatenated to a device ID, as follows:


The number of characters of a device instance ID, excluding a NULL-terminator, must be less than MAX_DEVICE_ID_LEN. This constraint applies to the sum of the lengths of all the fields and "\" field separator between the device ID and instance-specific-ID fields.

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:


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