E6400 on docking station with 24" monitor

​A user has a Latitude E6400 on a docking station with a 24" monitor attached to the docking station. The only resolution we can find that sort of works is 1024 x 768. But that leaves a black area to the left and bottom on the monitor. I've had her try to adjust the monitor, but it will not adjust out that far.​

​I'm not on site, so I don't know the exact model of the monitor or docking station, but they are Dell and were ordered and delivered with the laptop.​

​Looking for suggestions.​

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