How to safely change OS name in grub boot menu?
Open the grub configuration file:
sudo nano /etc/default/grub
Just comment the line starting with GRUB_DISTRIBUTOR and add one line:
# GRUB_DISTRIBUTOR=`lsb_release -i -s 2> /dev/null || echo Debian`
GRUB_DISTRIBUTOR="Ubuntu 15.10"
Afterwards, run
sudo update-grub
It should work after the next reboot. You will need to boot to both ubuntu installations and to change both names.
Important Note: Something you'll want to avoid doing is editing the file /etc/lsb-release and modifying the value for DISTRIB_ID which is read from the command lsb_release -i -s. While this does work to rename the grub menu entry (if you haven't modified /etc/default/grub), other programs also rely on the default name and may crash if it's modified (e.g. "Ubuntu" for Xubuntu). With that said though, kernel updates also replace this file, which will undo any changes to it.
There is a program called Grub Customizer that you can use for this. You can add, delete, move and rename entries. It also has a lot more features to set display resolution and so on.
See for yourself: https://launchpad.net/grub-customizer
Installation (Ubuntu >= 19.04):
The grub-customizer package is part of the default Ubuntu repositories:
sudo apt install grub-customizer
Installation (older Ubuntu versions):
The following steps are copied from the page above:
sudo add-apt-repository ppa:danielrichter2007/grub-customizer
sudo apt-get update
sudo apt-get install grub-customizer
Rename entry:
After the installation I have a new entry under Application > System Tools > Administration called Grub Customizer.
- Start Grub Customizer
- You will see the list of grub menu entries. Right click on one and choose "Rename".
- Enter the new name
- Click save in the toolbar and close the program
That's it.