And also it is that you have to make use of the files that are said to be the used for the manually adjusting the files and also they are just said to be used for the other files to. This is important whether you have to make use of the GPG keys and also for the use of the files for it, for the addition of the files in it:
This files are said to be important and I think it is said to be the best for the use of the files and also it can be seen that the Linux Mint is said to be the only system that supports the little bit factor of the files and also for the system of the files that can be sued for it.
Add GPG key:
gpg --keyserver subkeys.pgp.net --recv 55708F1EE06803C5
gpg --export --armor 55708F1EE06803C5 | sudo apt-key add -
update and install:
sudo apt-get update
sudo apt-get install grub-pc
After that you have to make use of the new startup code into MBR:
sudo grub-install "(hd0)"