Help Wrong aspect ratio with Dell Monitor

Wrong aspect ratio. I have a DELL E248WFP running with an Nvidia FX 5600. When I run in analog mode the 1920 x 1200 fills the whole display. When running in digital mode the 1920 x 1200 runs off the display left and right. I can get to each end by panning with the mouse but can’t seem to find a setting that will bring down the width to fit the screen. Does anyone know of something that I can try?

Thanks
Dennis