I'm trying to fully automate the process of Debian 9 installation, by using a preseed config file. The OS will be installed inside a VM on a remote headless server.

The only step which still requires user interaction is the main menu of the installer when I have to select the type of installation. See picture:
[![enter image description here](https://i.stack.imgur.com/dSB0z.jpg)](https://i.stack.imgur.com/dSB0z.jpg)

So how do I automatically select one of the options here? Specifically I want to select `Advanced options`, and then `Automated install`. I think by editing the `isolinux` files, I should get there, but I don't quite understand these files. According to this [article](https://sowhatisthesolution.wordpress.com/2016/03/13/headless-debian-install-via-ssh/) I modified the following isolinux files like this:

gtk.cfg

```
label installgui
    menu label ^Graphical install
    kernel /install.amd/vmlinuz
    append vga=788 initrd=/install.amd/gtk/initrd.gz --- quiet 

```

adtxt.cfg

```
default auto
label expert
    menu label E^xpert install
    kernel /install.amd/vmlinuz
    append priority=low vga=788 initrd=/install.amd/initrd.gz --- 
include rqtxt.cfg
label auto
    menu label ^Automated install
    menu default
    kernel /install.amd/vmlinuz
    append auto=true priority=critical vga=788 initrd=/install.amd/initrd.gz --- quiet 

```

But nothing changed. The cursor was still on the Graphical install, and I cannot afford user interaction.
Can someone point me to the right direction?