I have a Samsung 226BW flat panel with a 1680x1050 native resolution. As my PC is rather dated (Athlon XP 2600+ and GeForce 6600 GT), I need to run more recent games (but still old) on a lower resolution. Unfortunately, scaling low resolutions to 1680x1050 results in a very blurry image (bilinear scaling).

I have created a custom resolution of 840x525 in the Nvidia control panel. Technically, this resolutions allows perfect upscaling to 1680x1050 without the need for bilinear interpolation. Unfortunately, the Nvidia driver always seems to do bilinear scaling, again resulting in a blurry image.

However, I seem to remember that I did obtain crisp images using this resolution in the past (before a Windows re-install). Maybe only some driver versions support integer upscaling without bilinear filtering? Or perhaps there are other solutions?