Can anyone help me with this problem? A blue rectangular window has appeared in the centre of my screen. It is about 4 inches (10 cm) wide by 3.5 inches TALL. It floats on top of everything else, blocking out text beneath it. It has commands in it for screen settings: brightness, contrast, horizont position, vertical position, ETC. I cannot find any way of removing it or accessing it. It just seemed to appear for no apparent reason.
It appears at STARTUP during the bootup process, before Windows loads.
I have loaded an updated driver for the display

Operating SYSTEM: Windows XP SP2, 1.7GB, 40GB hard disk
Screen: Neovo LCD 19inch
RAM: 512

This sounds like the controls for your monitor.
The monitor should have buttons that let you move through the controls and some way of closing it. There's usually arrow or +/- buttons and an ok/MENU button.

Thanks deerpark
It definitely seems to be the monitor menu. The control buttons on the front of the monitor are inactive - must be something wrong with them. They don't respond when they are pushedIt sounds like a defective monitor to be honest.
If you can, connect it to another computer just to rule out the possibility of it being a defect in the computer that's causing this.