I have a Dell laptop in which I have dual booted Ubuntu with Windows 10. Usually the laptop loads the Grub menu first.
Recently I had some problems with Windows Bitlocker: every time I open Windows I am prompted to enter the Bitlocker password. In trying to solve this, I accidentaly clicked Ubuntu in the "Delete Boot" option in the boot sequence. Now the laptop boots directly to Windows without first loading the Grub menu.
Luckily, when I restarted the system and clicked "add boot option" I found the efi folder in which the Ubuntu folder is present. In Ubuntu there is fwgrupx64.efi, grubx64.efi, grub.cfg, shimx64.efi, mmx64.efi, and BOOTX64.CSV. On clicking grubx64.efi it shows "Boot name not found".
How can I recover the Grub boot menu?


