Tente isto:
Inicialize o Xubuntu Live-Usb.
Abra um terminal
Pressione Ctrl + Alt + T
Execute:
exec sudo -i
fdisk -l
Suponha que os relatórios do fdisk, / dev / sda1 = / e / dev / sda5 = / home, continuem a execução:
umount /dev/sda1
fsck -a /dev/sda1
umount /dev/sda5
fsck /dev/sda5
mount /dev/sda1 /mnt
mount --bind /dev /mnt/dev
mount --bind /dev/pts /mnt/dev/pts
mount --bind /proc /mnt/proc
mount --bind /sys /mnt/sys
cp /etc/apt/sources.list /mnt/etc/apt/sources.list
chroot /mnt
nano /etc/resolv.conf
No arquivo aberto, cole as seguintes linhas:
nameserver 208.67.222.222
nameserver 208.67.220.220
Ctrl + O
Salve o arquivo.Ctrl + X
Feche o nano.Continue em execução:
apt update
apt dist-upgrade
grub-install --root-directory=/mnt/ubuntu /dev/sda
grub-install --recheck /dev/sda
update-grub
umount /mnt/dev
umount /mnt/dev/pts
umount /mnt/proc
umount /mnt/sys
umount /mnt
reboot