Computer monitor:

When I set up the Display Properties screen resolution 800 * 600 time to look at the basic screen, but the display of text in the middle of a little gray, do not see the display on the edge of the clear position.And when I put the resolution to 1024 * 768 , The entire display interface is particularly fuzzy, but relatively speaking, than the middle or the edge of the clear.And when a movie screen and a special, if in the night scene, only to hear the voices, and people can not see A.
Now like to ask, I was a bad display them? Card or a problem.I would like to ask if there are no circumstances should emphasize how

display does not work.