Linux Mint: Fix bootloader Grub Windows (EFI and UEFI)

A computer that’s running in full UEFI mode, usually is a computer with a pre-installed Windows 8.x or 10 (64 bit edition). This how-to is therefore based on a 64-bit Ubuntu, that has suddenly “disappeared” from a dual boot machine that has also Windows 8.x or 10 on it.