in Ubuntu-Based distro (Ubuntu, Linux Mint, Elementary OS and others) the “Start up program” on Startup Applications Preferences dailog only appear partially, I do not know what the reason, but but there is one way to get all the startup program could appear in Startup Applications Preferences. when all start up application/program appear, you can disable the application for boost your ubuntu
Don’t disable any program that you don’t know what exactly it does, it may cause problems. Some programs really need be enabled as startup applications.
to show/Hide all startup Applications/programs in the Startup Applications Preferences dialog, you need to do is to run the following commands in the terminal.
sudo sed -i ‘s/NoDisplay=true/NoDisplay=false/g’ /etc/xdg/autostart/*.desktop
sudo sed -i 's/NoDisplay=false/NoDisplay=true/g' /etc/xdg/autostart/*.desktop
Now, you can easily to show/hide the unwanted programs that are set to automatically startup when system booting,