Win2grub Fix Jun 2026

The MBR is the first sector of a hard drive. It contains the partition table and a tiny amount of executable code called a "bootloader." The bootloader’s job is to locate an active partition and hand off control to the operating system kernel located there.

The operation of Win2Grub was a clever exercise in bootstrapping. It relied on the ability of the Windows NTLDR to load a sector from a hard drive or a specific file, rather than just loading the Windows kernel. win2grub

We tested a Dell XPS 15 (UEFI, NVMe SSD) with Windows 11 and Ubuntu 22.04: The MBR is the first sector of a hard drive

: The script cannot locate the Windows boot loader due to a hidden partition or different Windows version. It relied on the ability of the Windows

Usually, it’s at: \EFI\ubuntu\grubx64.efi or \EFI\fedora\grubx64.efi on your EFI System Partition (ESP).

While the name "Win2Grub" is sometimes used broadly to describe the general technique of bootstrapping GRUB from the Windows bootloader, it specifically refers to a set of scripts and executables used during the Windows XP/2000 era. Its primary function was to allow the Windows NTLDR to pass control to the GRUB bootloader without writing GRUB directly to the MBR.