I have a Samsung HD monitor that serves my desktop and laptop computers via an A/B switch. This setup has been working correctly for a couple of years. I use the recommended 1920 X 1080 resolution for both computers.
This morning the laptop screen is displaying correctly on the monitor, but the desktop's screen is offset about 2" to the right and shifted downward so the taskbar is not visible.
I have rebooted a couple of times with no success. I have tried adjusting the screen resolution on the desktop machine, and many resolutions fill the monitor screen correctly (but are either too coarse or distorted to use comfortably).
Does anybody know what could be causing this? The issue must be with the desktop machine, because the monitor is working fine with the laptop using the same resolution setting.