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Determining the Parent of a Device

Sometimes it is necessary to access the parent of a device. For example, the operation of some types of hardware devices depends on a fixed relationship between a specific parent and set of child devices. To uninstall such a hardware device, you must uninstall the parent in addition to all the child devices. To uninstall the parent, you must obtain a SP_DEVINFO_DATA structure for the parent. A Universal Serial Bus (USB) composite device, such as, a multifunction printer, is such a device. It is represented in the system by a parent composite device and one or more child interface devices (see USB Driver Stack Architecture). To uninstall a multifunction printer, you must uninstall its parent composite device in addition to all its child interface devices.

When the Plug and Play (PnP) manager configures a device in the system, it adds a device node (devnode) for the device to the device tree. When the PnP manager removes a device from the system, it removes the devnode for the device from the device tree, and the device becomes a non-present device.

To determine the device instance ID of the parent of a device, you can query the DEVPKEY_Device_Parent property on the device using SetupDiGetDeviceProperty. For a present device, this will provide you the device instance ID of the parent of that device. For a non-present device:

  • On Windows 8 and later:
    • If the parent of the non-present device from the last time the non-present device was a present device still exists as a device on the system (present or non-present device), DEVPKEY_Device_Parent will provide the device instance ID of that parent device.
    • If the parent of the non-present device from the last time the non-present device was a present device does not still exist as a device on the system, DEVPKEY_Device_Parent will return the device instance ID of the device that is at the root of the device tree.
  • Prior to Windows 8:

Once you have the device instance ID of the parent device, you can use SetupDiOpenDeviceInfo to obtain a SP_DEVINFO_DATA structure for the parent.