Table of contents

1. Introduction
2. Installation
3. ISO conversion
4. Adding a ISO to thumbdrive
5. UEFI boot
   1. Explanations and limitations
   2. If you have acess to BIOS mode
      1. Mount UEFI ISO
      2. Unmount UEFI ISO
   3. If you don't have acess to BIOS mode
      1. Mount UEFI ISO
      2. Unmount UEFI ISO

Introduction

This tutorial is a simplified version (with pictures) of the only functional way that i found to make a multiboot UEFI thumdrive. Is based on easy2boot, that is a free multiboot tool, and offers support to multiboot. This tutorial is based on windows version, because only windows version have graphical interface, and is easy to work.

Installation

• Download latest version from official easy2boot website (at time i write this is v 1.99) and install on your computer.
• Connect your thumb driver and certified that is correctly indentified by windows.
• Open easy2boot as administrator and select your thumbdrive. Be carefull to not select the wrong drive, and make shure you double checked drive, because all your data stored on the drive will be erased
• Click the red button make E2B drive and wait. E2B will automatically copy all necessary data to turn your thumbdrive in a bootable drive. This step can take a time, but don't worry, it's running.

ISO conversion

• In order to use multiboot on UEFI, you need to convert OS images from ISO to a image partition (.imgPTN). for this you will need mpi pack.
  Download and unzip
• Open unzipped folder and install imDisk (imDisk/imdiskint.exe)
• Double click CreateDesktopShortcuts.cmd to create three shortcuts on desktop (MakePartImage, MPI_FAT32 and MPI_NTFS), will be very usefull to convert images.
• Drag an ISO file to MPI_FAT32 and follow on screen instructions to convert to a partition image file (.imgPTN). If sucess, terminal background will turn green.

Hint: The partition image file will be created on same folder that original image (ISO) file.

Adding a ISO to thumbdrive

• Copy partition image created on previous step to your thumb drive, on correct folder (if is linux, to linux folder, if windows, to windows specific version forder). Its not mandatory, but mantains organization and easy to manage installed images. You can add many images as you want. The only limitaion is your driver capacity.
• After add a partition image file, run MAKE_THIS_DRIVE_CONTIGUOUS.cmd to ensure that all file are contiguous on drive. (If a partition image is not contiguous, will not boot)(And yes, you need to run this each time you add a partition image).

Pro tip: If you want to use a secondary partition (or even a third partition), make it before add the first partition image and run MAKE_THIS_DRIVE_CONTIGUOUS.cmd. This will ensure that your partition images won't corrupt.
In order to no override partition 2 and 3 (if applicable) when mount a partition image, simple rename partition image from <OS name>.imgPTN to <OS name>.imgPTN23. I.e. rename from windows10.imgPTN to windows10.imgPTN23.
Tip: Even if you have a second, but not a third partition, you need to rename partition image to <OS name>.imgPTN23 in order to not overrride then.
OBS: Due to some limitation on windows driver, only windows 10 (updated to april 2018 or newer) can recognize more tham one partitionon thumbdrive.

UEFI boot

(Explanations and limitations)

You will need a litlle hackish method to multiboot under UEFI. I don't know why, but seems that UEFI doesn't support multiboot natively (!?). It's nonsesnse, considering that BIOS (legacy) mode can do this like a charm. On UEFI, you need to switch partitions, to obtain only one UEFI bootable partition. Due to this limitation, you will need a little extra step over a traditional BIOS setup.

If you have acess to BIOS mode

Mount UEFI ISO

• Boot your thumbdrive via BIOS mode
• Select ISO you want to boot.
• Prompt yes. (This will replace your thumbdrive partition with partition image that you select)
• Press F9 to reboot machine and boot your thumbdrive on uefi mode

Unmount UEFI ISO

• Boot your thumbdrive via BIOS mode.
• Press 0 and enter to return to easy2boot menu

If you don't have acess to BIOS mode

Mount UEFI ISO

• Boot your pc on windows
• Open your thumdrive
• Navigate to _ISO
• Open SWITCH_E2B.EXE. This will list all partition images availabe on thumbdrive
• Double click to mount selected partition image
• Program will ask if you want to substitute partition table (like on BIOS mode). Prompt yes

Unmount UEFI ISO

• Boot your pc on windows
• Open your thumdrive
• Navigate to E2B
• Open SWITCH_E2B.EXE and click on button Restore E2B partitions