I have 9 columns of lines across the monitor screen. The lines are approx. 7/8 inch wide and are in vertical groups of 5-6 at bottom and 2-3 at top of screen at startup. When I scroll, the bottom set of lines form columns from bottom to top of screen. The lines appear in green at bottom and blue at top against a dark background. When the background is light, the lines are pink at bottom and yellow at top. I have tested 3 monitors (2 lcd and 1 crt) with the lines appearing in all 3 - monitor is obviously not the problem. Any ideas?