Vista - How can I reset external monitor settings?

Hello everyone!

I find myself in a very frustrating predicament. Yesterday I tried connecting my laptop to my 46" Samsung TV (LN46A650) using a top-end VGA cable, and it worked beautifully out-of-the-box. I was able to get a resolution of 1280 x 768 mirrored, and, more importantly, 1920 x 1080 when using only the external monitor. It looked gorgeous, and I should've left well enough alone. Unfortunately, I started to experiment with different resolutions, extended desktops, etc. I don't know exactly what I did, but the end result is that I can no longer get the "external monitor only" mode! When I try to switch to that mode, either by pressing Fn-F8, or through Windows Mobility Center, or through nVidia control panel, the resolution gets reset to 800 x 600, and image is displayed on BOTH the laptop and the TV.

I spent about 3 hours last night trying to fix this problem. I tried logging out, restarting the computer, turning off the TV, disabling Transient Multimon Manager (TMM) and restarting, and uninstalling the monitors from the Device Manager. The latter automatically reinstalls the monitors and gives me the "New Display Detected" screen, but the "Show my desktop on the external display only" option is grayed out:




So, I'm left wondering if it's possible to reset external monitor settings to "factory defaults" to get the "external monitor only" 1920 x 1080 mode working again. After all, IT WORKED BEFORE, until I started messing around. Where are the settings for external displays stored, anyway? Is it a Vista thing, an NVIDIA thing, a Dell thing, or some bastardized combination of the three? Please help!

P.S. Unfortunately, I did not have System Restore enabled, so rolling back is not an option.

Hardware/software: Dell Precision M6300 laptop with an NVIDIA Quadro FX 1600M video card, running Vista Business 32bit. Updated with all the latest drivers.

Did you switch back to Extended desktop mode from Clone mode for the
external display?

"agaethwe" <guest@xxxxxx-email.com> wrote in message
news:d1481b33e0d55a5a60ee6a16408b6a31@xxxxxx-gateway.com...

I don't want the Extended desktop mode, I simply want an external display with my laptop screen blank. I definitely unclicked "Extend the desktop onto this monitor" for the external display. In any case, I did a little further research and may have solved my own problem. The external monitor configurations are apparently stored in HKEY_CURRENT_USER\Software\Microsoft\MobilePC\TMM\VidList in the registry. When I get home, I'll try deleting them and see if it fixes the problem.

If you want to use a different resolution on the secondary display you can
only do that using extended desktop mode instead of clone mode. It is very
easy to just drag and drop a copy of the desktop Icons that you want to use
on the secondary display or to drag and drop a running application from one
to the other.
If the secondary display will not accept the resolution being used on your
primary display with the interface you are using you will see nothing in
Clone Mode.

"agaethwe" <guest@xxxxxx-email.com> wrote in message
news:02b4467fa92d87ee5ab00274b7db7b81@xxxxxx-gateway.com...