Why is my laptop not displaying a picture on an external monitor through a DVI cable?

1. Check that the cable is correctly connected to both the laptop and the external monitor

2. Check the settings on the laptop and the external monitor

3. Ensure that both the laptop and the external monitor are powered on

4. Verify that the laptop has both a DVI output port and up to date DVI driver software

5. Check that the laptop is not in sleep mode

6. Troubleshoot the DVI cable by testing it with another external monitor or replacing it with a new DVI cable

7. Verify that the external monitor is compatible with the laptop