Ntboot7z May 2026

WIM files are even more space-efficient than ISOs. To boot a Windows PE WIM:

ntboot7z wim=/sources/boot.wim index=1

The index parameter selects which image inside the WIM (e.g., 1 for Windows PE, 2 for Windows Setup).

Technicians often carry USB drives containing Windows PE (Pre-installation Environment) tools for fixing broken computers. By using ntboot7z, an entire WinPE environment can be stored as a highly compressed 7z file (often under 100MB), saving significant space on the USB drive and speeding up the boot process compared to copying thousands of small files.

IT pros can create a "golden image" of Windows with all drivers and apps, compress it to .7z, and deploy it to multiple machines by simply copying the file and configuring boot entries. ntboot7z

UEFI is more complex because it requires a working ntboot7z.efi and proper Secure Boot handling (you may need to disable Secure Boot or sign the EFI).

GRUB2 entry (/etc/grub.d/40_custom):

menuentry "Windows 11 ISO (NTBoot7z)" 
    insmod part_gpt
    insmod ntfs
    set root=(hd0,gpt1)
    ntboot7z --efi=(hd0,gpt1)/EFI/ntboot7z.efi iso=(hd0,gpt1)/isos/win11.iso

Then run sudo update-grub.

Traditional booting requires:

This consumes space and is vulnerable to corruption. System administrators, forensic analysts, and repair technicians needed a way to:

ntboot7z was created by the developer Chenall (of grub4dos extension fame) to bridge the gap between high-compression archives and the Windows boot process. WIM files are even more space-efficient than ISOs

While NTBoot7z is powerful, be aware:

If you dual-boot Linux and Windows, your GRUB bootloader is already in place. Adding NTBoot7z as a menu entry takes 30 seconds. You no longer need to rely on Windows’ buggy boot manager.

If you have windows.7z containing an ISO inside, you can do: The index parameter selects which image inside the WIM (e

ntboot7z 7z=/compressed/windows.7z iso=windows.iso

This extracts only the ISO’s boot sectors from the 7z archive.