I'm currently having an issue installing 18.04.1 from USB on a Zoostorm 7270-8006 Ultra Small Form Factor PC.
I can boot into the Ubuntu installer or the "Try Ubuntu" mode and get the desktop with the orangey beaver background. However, there are no icons. Right-clicking gets me the desktop context menu from which I can get a terminal up.
After a bit of experimentation I realised that the system is acting as if there are multiple monitors, even though only one is connected. When I move the mouse off the left of the screen it keeps going for some distance and takes as long to get it back. Maybe there are icons over here, but I can't see them to click on them.
It doesn't seem possible to turn off other monitors in the BIOS. I've also tried connecting both VGA and HDMI monitors, but neither of them have the icons or setup screen, just the background image!
So what I'm looking for is a way to force a live install like this to use only one monitor, ideally with a command line command. Once the system is set up I know how to use System Settings -> Screen Display to achieve this, but that's not available to me at the moment.
I used xrandr to workaround this issue as follows:
Shows two monitors:
Then I used xrandr to turn one of them off.
Icons appear!
Once installed you can make these changes permanent (after login) by putting the xrandr command into your .profile.