Horizontal Coloured Lines in ppt

Question

One day when I was getting my PowerPoint on the screen on a cruise ship, instead of seeing the image of my Presentation I got a series of horizontal lines of many colours.I use an Acer laptop and go through the icon Acer E-manager and then choose Acer E-Presentation and then the XGA setting.In order to repair it I had to go to the Normal setting and back to the XGA setting and the problem was corrected.However Saturday night in anticipation of church group it happened again and this time I couldn't reverse it. Even when I rebooted. I had to download the ppt presentation and run it on another laptop, where it worked.What is the reason for the horizonal coloured lines?