The contrast box has a color bar that changes from red to blue and back again.
The cursor has no effect on it.
There are different pictures showing how to chenge the shape of the screeen.
There is an exit sign on the left side.
The numbers 9300 and 9500 are in the box
User mode H:37.8KH2
What you are describing is the monitor setup screen. Usually there is a menu button and cursor keys on the monitor.
If it appears without your action, I would guess that it wants you to change that setting. 9300/9500 sound like color temperature setting - that is a matter of visual preference. H: is horizontal frequency - adjust that if the monitor image is unstable or if it has artifacts sprinkled throughout the screen.
It's possible that the graphics card is being asked for to high of resolution or the number of colors. Back off to VGA (800x600) and 16 million colors (256 is web pallete).