Why is my computer not displaying correctly on an external monitor connected with VGA after a Windows update?

1. Check to make sure cables are connected properly.
2. Check that the monitor has both power and signal sources.
3. Verify the monitor is compatible with the graphics hardware and the video cable.
4. Ensure the correct display settings are applied.
5. Make sure the video drivers are up to date.
6. Test the monitor on another computer, if possible.
7. Attempt to revert to a previous version of Windows, if possible.