...If the problem is a desktop computer is to borrow another monitor and swap it in to see if the problem continues..If the replacement monitor displays correctly then you know it's time to replace it.
If the replacement monitor is also showing the same symptoms, then try reinstalling the video driver.
By the way, whenever posting questions on these forums, please give us as much information as possible about your computer. Depending on your issue, we might need the operating system, processor speed, amount of RAM installed, brand name of the computer, (if there is one), and any EXACT error messages you are receiving,plus any other info you think might be helpful. The more information you give us, the better informed our answer will be.
Hope this helps.
I have small boxes and lines every where on my computer display. I have run Norton virus scan, and found nothing. I think it may be a hardware problem, but I am not sure. (did have problems booting up, but I could not read anything on the screen.) Has anyone had thins happen, or know what I could try?