Computer monitor

All of the cables and connectors got the 42-inch TV monitor connected to the computer. The monitor is capable of being a display screen/monitor or/viewer for a computer. After all of the connection trouble, I find that it is not satisfactory, everything is larger, but the definition is not adequate. You have to be about five feet from the screen and the monitor is sitting on the bureau, and so it is higher that is comfortable to sit and use. All seemingly good ideas do not work.