|Your problem could be caused by a hardware problem including that caused by physical damage, or by you setting the resolution to the wrong setting in Windows, or if you have an external CRT (tube) monitor, by the display needing to be adjusted on the monitor itself. |
You need to tell us
- whether this is the built in display on a laptop or netbook
- if it IS a display on a laptop or netbook,
- the specific make model of it
- Have you, or is it possible someone else who had access to this computer...
- dropped it, or dropped anything on it, or otherwise exposed it to a physical jolt ?
- spilled liquid on it, or sprayed it with liquid, or exposed it to liquid such as rain ?
Since the video last worked properly all the time, has there been a power failure event that happened while the AC adapter was plugged in ?
- if it's NOT the built in display on a laptop or netbook, if it's an LCD, LED LCD, or Plasma display, what the make and model of the monitor or TV is