PVOID HwDeviceExtension,
      PVOID HwContext,
      PWSTR ArgumentString,
      PUCHAR Again

Routine Description:

    This routine is called to determine if the adapter for this driver
    is present in the system.
    If it is present, the function fills out some information describing
    the adapter.


    HwDeviceExtension - Supplies the miniport driver's adapter storage. This
        storage is initialized to zero before this call.

    HwContext - Supplies the context value which was passed to

    ArgumentString - Supplies a NULL terminated ASCII string. This string
        originates from the user.

    ConfigInfo - Returns the configuration information structure which is
        filled by the miniport driver. This structure is initialized with
        any known configuration information (such as SystemIoBusNumber) by
        the port driver. Where possible, drivers should have one set of
        defaults which do not require any supplied configuration information.

    Again - Indicates if the miniport driver wants the port driver to call
        its VIDEO_HW_FIND_ADAPTER function again with a new device extension
        and the same config info. This is used by the miniport drivers which
        can search for several adapters on a bus.

Return Value:

    This routine must return:

    NO_ERROR - Indicates a host adapter was found and the
        configuration information was successfully determined.

    ERROR_INVALID_PARAMETER - Indicates an adapter was found but there was an
        error obtaining the configuration information. If possible an error
        should be logged.

    ERROR_DEV_NOT_EXIST - Indicates no host adapter was found for the
        supplied configuration information.