This has happened several times and will sometimes correct itself (or beating it may help?) I go on the road for a trip and go to using just the laptop monitor instead of my external monitor and when I boot up the laptop the screen is black though I can hear Windows loading in the background. When I return home the laptop recognizes the external monitor but will not even show the laptop monitor in the display settings. I have tried updating the drivers with no luck. Any suggestions?
Chrimarsh: I have the same (or similar) problem with a Compaq laptop. If I turn on the laptop without the external monitor, the laptop display is black. But if I connect an external monitor, it's working, as though the laptop recognized the external monitor at start-up, even though it wasn't connected. When I check Display settings in Windows 7, it doesn't show the laptop monitor at all - it's as though it doesn't even exist. Using the function key to try to engage the laptop screen is useless since the operating system does not even recognize that it is there.
If I have the external monitor connected when I start the laptop, both monitors are recognized and everything is mirrored on both. So it's only recognizing the laptop display when an external monitor is attached at power-on.
The machine will occasionally surprise me and work properly - about one time out of 25.
I have upgraded the display drivers and the system BIOS from the manufacturer. When that didn't work, I tried rolling back to the Win 7 installed drivers. That didn't work either. It's almost as though the on-board graphics adapter recognizes the external monitor even when it's not there, and only looks for the internal display if it finds the external one.
Is this the same thing you are seeing? And if so, have you found a fix?