Quote:
is there any command for grub2 to update the installed os again?
|
sudo update-grub or login as root (su at the terminal prompt), enter your root password and run: update-grub.
There is also a program called os-prober which may not be installed by default. If the update command doesn't get everything, run os-prober as root, if it returns a message not installed, as root: apt-get install os-prober.