Why does my computer monitor flicker?

What causes a personal computer's monitor screen to flicker sometimes?

• Answer:

  Your monitor is probably alright. If it was going bad, you would most likely start to see a constant black stripe on the top or sides. Some monitors naturally flicker some when playing videos, such as certain Acer flat-screen monitors. It could be a sign that you are using the wrong refresh rate or the wrong video card driver settings. Try updating or reinstalling the video card driver (the software that runs the video card). You could be running low in RAM or just hard drive space, so try removing unwanted programs, games, pics, videos and even documents. Then defragment the hard drive. This would more likely just address a jerky display, not actual flickering. Check that your PC's fan is not clogged with dust, to make sure the system is not overheating. Sometimes malware (viruses and spyware) can cause video issues. For instance, one type of spyware displays a green dot in the upper left corner of the screen.