def data(self):
    """bytes: value data as a byte string.

    Raises:
      WinRegistryValueError: if the value data cannot be read.
    """
    try:
      return self._pyregf_value.data
    except IOError as exception:
      raise errors.WinRegistryValueError(
          'Unable to read data from value: {0:s} with error: {1!s}'.format(
              self._pyregf_value.name, exception))