I have found a tool that allows to customize and then save Grub menu changes such as:
1) Which operating system loads by default
2) The amount of time the startup prompt option takes before starting automatically
This is usually the first customization task I need to do whenever I dual boot Linux and Windows.
The graphical tool’s name is grub-customizer and it is available from an Ubuntu ppa repository. The developer’s profile is here
sudo add-apt-repository ppa:danielrichter2007/grub-customizer sudo apt-get update sudo apt-get install grub-customizer