CRTs have improved to the point where burn-in is less of a problem, and screensavers have become more a means of entertainment than a solution to a technical problem. In fact, many use largely static images- such as an aquarium tank- in which only a small portion of the image changes.

LCD’s can also be susceptible to image burn-in, though it isn’t as common as with CRTs. If you’re going to use a screensaver, it should have a black background with a small moving image. The best solution, however, is to use energy-saving feature within Windows, telling the monitor to shut off when the system has been idle for a given period. This will not only prevent burn-in but also save energy. Plus, it can extend the life of the display. An LCD uses a backlight that loses brightness over time, so it’s better to turn off the monitor- and thus the backlight- than to leave it on for some entertaining screensaver. An additional benefit for notebooks. Turning off the display when idle can significantly extend battery life.