Hi.
I have installed the latest Debian Stable version last week. I'm using the LXDE environment. My main problem is:

I am using an old netbook/laptop with a small screen. So, to improve thing I attached an external Dell monitor to it though the VGA port. After connecting the cable to the port, I go to Menu -> Preferences -> Monitor Configuration. In the pop up window I choose the option: Turn off the laptop LCD and use only the external monitor. Then, I click APPLY, then, SAVE.

The problem is that everytime I restart the laptop the login screen appears only in the laptop and I have to do everything mentioned above again! Not only that, most of the times I need to disconnect the VGA cable for things to work properly while the login screen is up.

How can I solve this problem?
Thank you.

P.S.: Laptop is a LG model X140.

I'm not sure precisely how to do in in LXDE, but I know how to do it in XFCE4. My solution is to use arandr to set up my desired multi-monitor configuration and save it to a bash script file. Then I go to the Sessions and Startup settings in XFCE4 to add that bash script file to the list of startup things.

I also insert the line "sleep 4" in this script to ensure it waits a while before running. XFCE4 can get confused if another program is redefining the xrandr settings at the same time it is.

With XFCE4, though, no such scripting is required for your case. By default, XFCE4's built in display settings remember which monitors you want to be active, and the resolution. If you only want one monitor active, then that's good enough. Unfortunately, it's not good enough for a typical multi-monitor setup because the XFCE4 display wizard only allows overlapping screens (all sharing the same top left corner).

You may be able to disable the screen at KMS level with kernel command line switch. I had a box once that defaulted to non-existing output, kernel command line allows for enabling and disabling outputs at your will. Duckduck ...

OK, here's what Duckduck gave: https://www.osadl.org/Single-View.11...38a7b3b.0.html

Check out the section about disabling/enabling connectors.