I am helping a friend with a Dell laptop, inspiron 8200. His window, when set to 1024×768, only covers 1/3 of the center of the screen. In other words, there is a 2.25 inch black band around the Windows OS. My Dell, a different model, when I set the resolution, sill allows Windows to cover the whole screen. I believe he had been using the resolution successfully previously, though I cannot be 100% sure. I do know that he did not intentionally change resolutions and the Icon layout changes at different resolutions.
I know that 1024×768 is not the native resolution, but I have never seen an LCD that did not allow one to use the non native resolution, it simply complains.