I'm currently having a problem with my system where the full 2560×1440 resolution of my Dell U2711 monitor isn't well supported by my ASUS G73S laptop (it has an NVIDIA GeForce GTX440M CUDA with 1.5GB RAM). The laptop doesn't have DVI-D or DisplayPort outputs and the monitor doesn't officially support that resolution over HDMI. So, to work around it I added a "Custom Resolution" in the nvidia control panel. This works until the computer sleeps or reboots, at which point it stops working and the display driver freaks out, refusing to display on either the internal or external display until I unplug the HDMI connector.
In fact, the whole machine seems to lock up when I plug in the monitor as I can't VNC into the computer, either.
Unplugging the external monitor returns functionality for a while, but as soon as I plug it back in I'm stuck again.
If I get the external monitor to show a lower resolution I can successfully "upgrade" the resolution – I just have to make sure the laptop first uses the default 1920×1080 resolution that is better supported. Then I can increase that afterwards. To do that I have plugged in the VGA connector to the monitor which seems to have changed Windows' idea of my monitor configuration enough that it resets things to defaults. However, I suspect that if I reboot my computer without downgrading the resolution first I'll be in trouble … I don't have any more monitors to hook up to use this trick!
I'm hoping that I can find a way get the various system components that restore my prior screen resolution to forget those settings so that if I get in trouble I can unplug the external monitor, delete/forget all those remembered display settings, and plug it back in to get to the "defaults" of 1920×1080 on both displays.
The ASUS driver updater tells me I have the latest drivers installed. I tried a quick search to see if there are still "third party" video card drivers out there but I didn't see anything.
Any ideas?
Best Answer
I found a way.
I went to the registry key HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\GraphicsDrivers and deleted subkeys that had DELA in them. These are apparently the keys windows uses to decide what display settings to use when the display configuration changes. Deleting them caused windows to forget the settings and when I plugged the external monitor in it reverted back to mirroring both monitors at a lower resolution that worked.
Special thanks to sysinternals process monitor tool which I spent a while using to see which registry keys were read and written when I plugged in and unplugged my monitor.
Yay!