VOID
InbvSetProgressBarSubset(
      ULONG Floor,
      ULONG Ceiling
  );

Routine Description:

    Sets floor and ceiling for subsequent calls to InbvUpdateProgressBar.
    While a floor and ceiling are in effect, a caller's 100% is a
    percentage of this range.   If floor and ceiling are zero, the
    entire range is used.

Arguments:

    Floor   Lower limit of the subset.
    Ceiling Upper limit of the subset.

Return Value:

    None.