my computer is a small tablet which is now over six years old, which may not be that old under normal conditions but the tropical humidity is hard on electronics and optical instruments :-( .in case of my tablet this means black horizontal lines started to appear on both top and bottom a few months ago and they're getting more and wider, after a few minutes vertical lines with the colours playing up start to appear as well which makes for an increasingly lousy picture quality :-( :-( i'm afraid that's beyond repair...I had the same problem late last year, a 7 year old laptop, now glitching and very slow. So, I backed up all my data files, bought a new SSD drive and a new Windows 10 license, and hey-presto for less than £150 a new faster laptop