Many display problems can be solved by updating your video drivers. It is generally a good idea to keep drivers up to date as they can be updated quite often by the manufacturers.
There may be other things you can do as well in particular cases. Click the description below of the problem you are experiencing:
If none of these descriptions matches the problem you are experiencing, please email firstname.lastname@example.org with a detailed description of the problem as well as information about your video card.