Accessing Custom Settings
In Windows Vista and later versions of Windows, the unified device property model supports using property keys to create and access custom device properties. For more information, see Creating Custom Device Properties.
On Windows Server 2003, Windows XP, and Windows 2000, you can create custom registry entry values under the system-supplied registry keys for a device-related component. The following list contains the SetupAPI function to call for each type of device component to open the corresponding system-supplied registry key. After you open the system-defined registry key, applications and installers can call the Windows-based registry functions to modify custom registry entry values under the open registry key.
A custom registry entry value for a device instance hardware property should be located under the hardware registry key of a device instance. Call SetupDiOpenDevRegKey and supply DIREG_DEV in the Flags parameter to retrieve a handle to the hardware key of a device instance. Custom registry entry values that are set under the hardware registry key for a device instance can be retrieved by calling the SetupDiGetCustomDeviceProperty function.
A custom registry entry value for a device instance software property should be located under the software registry key of a device instance. Call SetupDiOpenDevRegKey and supply DIREG_DRV in the Flags parameter to retrieve a handle to the software key of a device instance.
A custom registry entry value for a device setup class property should be located under the device setup class registry key. Call SetupDiOpenClassRegKeyEx and supply DIOCR_INSTALLER in the Flags parameter to retrieve a handle to the registry key for a device setup class.
A custom registry entry value for a device interface class property should be located under the device interface class registry key. Call SetupDiOpenClassRegKeyEx and supply DIOCR_INTERFACE in the Flags parameter to retrieve a handle to the registry key for a device interface class.
A custom registry entry value for a device interface property should be located under the device interface registry key. Call SetupDiOpenDeviceInterfaceRegKey to retrieve a handle to the registry key for a device interface class.
After you retrieve a handle to a registry key, supply the handle in a call to RegQueryValueEx or RegSetValueEx to retrieve or set the custom registry entry value that corresponds to the custom device property.
Call the RegCloseKey function to close the registry key after access to the registry key is no longer required.