When presenting a back buffer of a certain resolution (say 1024x768) to the
screen (e.g. 1600x1200), XP always seems to do this using a linear filter.
Meanwhile with Vista, a point filter is applied leading to poor results.
This applies to both NVidia and ATI cards with different driver version.
What can be done about that? Can the filtering done during Present() be
controlled somehow?

Thank you very much
Robert

Addition: For several reasons, I have to work in windowed mode (as "false
fullscreen" mode).

To be a bit more precise:

The DirectX SDK Documentation says:

-----
IDirect3DDevice9::Present
...
If necessary, a stretch operation is applied to transfer the pixels within
the source rectangle to the destination rectangle in the client area of the
target window.
-----

What filter is applied for that stretch operation, and can it be controlled
by the app?

Thank you again!
Robert

I have also observed that linear interpolation is perfomed in this
case, and I am not aware of any way to control this directly.
However, it can easily be avoided by simply rendering into a
rendertarget that is the same size as your window, and then selecting
whatever interpolation type (point or linear) that is appropriate.
This may mean an additional render pass than what you currently have,
but that's essentially what used to be happening on XP anyway.

--Matt

Thank you, I have implemented it like that and it works as expected.