I hooked up a 22" LCD to my Dell Vostro 1400 (with GeForce 8400M GS running Vista Business) and use the LCD as an external display. Originally I used the Nvidia Control Panel to set it so that the primary display and single display used was the external LCD, which the control panel recognized fine. I could close the lid of my laptop and use the LCD as a monitor with no problems.
Recently, I went through some resolution altering when setting up a game, and now whenever I close the lid of the laptop, I get a "out of range" problem on my LCD and no image shows up. However, opening the lid of the laptop allows the picture to come back on the LCD, although the laptop screen is black. I run the LCD at 1680x1050 at 59 hertz refresh and the laptop screen runs with a 1200x800 resolution at 60hz refresh (the LCD can display 60hz).
I tried System Restore and that didn't work. How can I get my external LCD working again with the laptop lid closed?
EDIT: I fixed the problem by booting into safe mode. While I didn't do anything in safe mode, when I rebooted normally, this problem went away.
