Restore EFI Boot

Boot a Ubuntu USB (Esc,F12 or F8 on boot) Select "Try Ubuntu" In Terminal Determine whether your computer is in EFI or Legacy mode first ls /sys/firmware/efi must exist sudo fdisk -l gparted Created a new partition at the beginning of the disk Format the partition as a FAT partition and must set to type EFI sudo mount /dev/sda2 /mnt sudo mount /dev/sda1 /mnt/boot/efi for i in /dev /dev/pts /proc /sys /run; do sudo mount -B $i /mnt$i; done # Prepare chroot environment sudo chroot /mnt # activate chroot and set /mnt as root grub-install /dev/sda # reinstall grub: sudo update-grub # make sure /etc/fstab and correct UUID # eg UUID=D303-EB8B /boot/efi vfat umask=0077 0 1 sudo blkid /dev/sda1 sudo update-grub

Glenn Lyons VK4PK
Ver:gnl20220603 - pre published v0.9