Does Windows key + P combination help at all?
I don't understand completely, though. You say that it only displays now on the projecter, but all attempts to detect it fail. It can't be both lol. Can you please clarify this for us?
If the combo doesn't offer you a solution, boot to normal mode and use the device manager to manually uninstall the graphics driver. Power off. Remove any external display. Power on to Windows and it should reinstall the driver automatically by finding it. If not, install yourself.