I'm trying to switch from a twinhead dual monitor setting, to a single monitor setting. I was pretty sure I knew how to do this, but when I come to do it in anger, I just can't get it to work.
Here's what's happening:
System>Administration>NVIDIS X Server Settings
I select X Server Display Configuration
Click on my Samsung monitor image, the monitor I want to disable.
Click on the Configuration box
Select the Disabled option, click on OK
Click on Save to X Configuration File
The Save X Configuration window opens, I can see /etc/X11/xorg.conf, and the merge with existing file box is ticked.
I click on Save, and get the message:
Unable to remove old X config backup file '/etc/X11/xorg.conf.backup'
I click on OK, the only option, and Quit
And nothing happens.