Trying boot from livecd to fix the dual boot issue.

[email protected]:~$ sudo grub-install /dev/sda

/usr/sbin/grub-probe: error: cannot find a device for /boot/grub (is /dev mounted?).

Solution:

set the /boot/grub path

[email protected]:~# mkdir /a; mount /dev/sda1 /a # sda1 is the root you installed linux

[email protected]:~# grub-install /dev/sda –boot-directory=/a/boot/grub

Installation finished. No error reported.