Ubuntu+windows Repair Grub Boot after dual system reload windows

Enter Ubuntu's trial interface via Live CD.

Open terminal and enter the following command:

Sudo-i

Fdisk-l

(Find your Ubuntu installed on that partition)

You can also directly open the hard drive management to find out where Ubuntu is on your hardware.

such as my Ubuntu in the SDA10 partition.

Mount the root directory of the original system below:

Mount/dev/sda10/mnt

(10 replaced with your Ubuntu partition number)

Grub-install--ROOT-DIRECTORY=/MNT/DEV/SDA

(Note: There is a space bar behind/MNT)

If you see

installation finished. No Error reported.

Reboot Restart

It means it's done! Reboot to see if the familiar Grub boot screen is back again?

This is a good time to go to Ubuntu, then restore grub, or My computer will prompt for errors.

sudo update-grub

Ubuntu+windows Repair Grub Boot after dual system reload windows