Abstract: A window covering offers significant options and control with respect to the amount of light that enters a room. The invention is embodied in a first illustrated embodiment with an upper blind portion that has a head rail attached to a header plates and which is adjustable from the top down, and a separate lower blind portion that has a bottom rail attached to the sill plate and is similarly but independently adjustable from the upper blind portion. The two portions in combination provide a highly variable window covering system. In an alternative embodiment, the upper and lower components of the window covering share a middle rail that defines a lower rail for the upper component, and an upper rail for the lower component, in which the upper and lower rails of the respective upper and lower components are separable from the associated header and sill plates.