Add payload files to partition 2 or 3

Typically, an E2B USB drive will contain two or three Primary MBR\Legacy partitions (the last partition table entry must be empty):

Ptn1: NTFS (E2B files)
Ptn2: FAT32 (agFM files)
Ptn3: (optional) NTFS (recommended)/exFAT/FAT (optional user folder)
Ptn4: (unused\empty)

GPT partitions are not supported. You can add other files and folders to any partition.

If you have a large (>128GiB) USB hard disk, I recommend that you use the first NTFS partition (up to 128GiB in size) for E2B and use the second partition for other purposes such as for the agFM files, storing utilities, hard disk backups, documents, etc.

Note that only  recent versions of Windows 10 (1703+) can access the 2nd partition if it is on a Removable (flash) drive.

If you do create a 3rd Primary partition, be aware that this may limit some features of E2B (e.g. being able to use a Linux ISO with persistence).

However, you can place most payloads such as linux .ISO files, Windows VHD files, etc. on the second (or third) partition and add the PTN2_MNU.mnu menu file (find it in the \_ISO\docs\Sample mnu Files folder) to one of the standard E2B menu folders (e.g. add it to the \_ISO\MAINMENU folder).

The PTN2_MNU.mnu will take you to a sub-menu where all the files in a folder on the second partition will be listed and you can then boot to any one of them.

You can rename the .mnu file to something more suitable.

It is best to use a similar folder structure to Partition 1 (e.g. \_ISO\ANTIVIRUS) but you don’t have to.

Note: Windows VHD files will only boot from partition 2/3 on a Removable USB drive if the VHD contains Windows 10 1703 or later. However, there should be no restriction if the E2B USB is a hard disk. 

\_ISO\WINDOWS\xxxx

E2B has a special feature which allows you to place large Windows ISOs on the 2nd/3rd partition if you do not have enough room on Ptn1.

This assumes that your E2B files are in the first partition and you have created a second or third Primary NTFS or FAT32 partition on the E2B drive (and have removed the very small 2nd partition that Make_E2B.exe usually makes).  Check that two or three Primary partitions are present using ‘RMPrepUSB.exe – Drive Info – 0′. 

Note that some BIOSes have a bug in their USB driver and they cannot access files past 128GiB, so if the 2nd partition is beyond 128GiB you may experience strange grub4dos errors, etc.  E2B will warn you if the BIOS is buggy when it first boots. Sometimes you can fix the BIOS driver by loading the grub4dos USB 2.0 driver (use a USB 2 port instead of a USB 3 port). If booting Windows ISOs from an E2B ‘fixed-disk’ USB drive and NOT using WIMBOOT, you must also connect a WinHelper ‘Removable’ USB flash drive so that Windows will load the XML file and use ImDisk to load the ISO file as a virtual DVD drive. 

Choose a Windows ISO from partition 2 or 3

You can add Windows ISOs to the second or third partition as follows:

This example is for a Windows 10 ISO (XP ISOs are not supported on partition 2/3). 
If your E2B USB drive is a removable USB drive (e.g. Flash drive) then only Windows 10 or later ISOs will work from partition 2/3.
If the partition is a FAT partition, you will be limited to ISOs of less than 4GB in size.

1. Copy the whole \_ISO\WINDOWS\WIN10 folder to the second partition so that there is a \_ISO\WINDOWS\WIN10 folder containing the standard XML and .key files, etc. 
   Do NOT copy the \_ISO\WINDOWS\installs folder – this must only exist on partition 1.
2. Copy your Windows 10 ISO file to this new folder.
3. Create a small dummy file (of identical name and path of the ISO) in the first E2B partition. An easy way to do this is to copy and then rename one of the small .key files. Any small file can be used but it must be greater than 0 bytes in size. e.g.

Partition 1\_ISO\WINDOWS\WIN10\Win10x64.iso (any non-zero size – any contents)
Partition 2\_ISO\WINDOWS\WIN10\Win10x64.iso  (5GB) + folder contents 

When you can select the ISO from the Windows menu (all .iso files will be listed), E2B will detect if there is an identical ISO on the 2nd/3rd partition and will use that instead.

E2B will also prompt you with a list of the .xml and .key files that are present in the same partition that the ISO file is in. 

You can add any number of ISOs in the same way. 

If you want to delete any ISO, remember to also delete the small dummy ISO file on partition 1 or else it will still be listed in the Windows Install menu (but it will display an error if you try to boot from it)! 

Note: If your E2B USB drive is of the Removable type (flash drive) then this method will only work with later versions of Windows 10 (1703 and later), because earlier versions of Windows can only access the first partition on a Removable drive. 

Add a menu entry for a Windows ISO on Partition 2/3

You can add a .mnu file into a menu folder (e.g. \_ISO\MAINMENU) to directly boot to one of the Windows ISOs in partition 2 or 3.

A ‘dummy’ small ISO file on partition 1 is not required. You can also specify an XML file if you wish. 

See the sample menu file “\_ISO\docs\Sample mnu files\Windows\Win10_8_7_ISO_on_PTN2.mnu” for an example (or Win10_8_7_ISO_on_PTN2.mnu). 

Copy the .mnu file to \_ISO\MAINMENU folder and then edit the file to change the ISO name, etc. If you want to be prompted to choose a key or XML file, use set XML= in the .mnu file. 

Install Windows from a ‘True Hidden’ E2B drive

[For ‘expert tweakers’ only!]

If you use the ‘True Hide’ option (as added by the PimpMyDrive.cmd script), then it is possible to completely hide and make inaccessible the first NTFS E2B partition from Windows OS’s.

You can still MBR-boot from it to the E2B menu and run most of the payloads (with some exceptions such as some WinPE WinBuilder ISOs and other Windows-based payloads). However, it means that you cannot install Windows from the hidden partition because Windows cannot find the ISO file. 

Here is a rather complicated way around it! 

Note: If using a Removable E2B USB drive, this only works for Windows 10 1703 or later. 

1. Ensure the E2B partition is accessible – unhide the E2B drive by booting to the E2B menu and choosing the True Unhide (hd0,0) option.

2. Copy the \AutoUnattend.xml and \Unattend.xml files to the root of the 2nd partition

3. Copy the whole \_ISO\e2b\firadisk folder to the 2nd partition (keep the same folder structure)

4. Copy the Windows ISOs to the 2nd partition (as described above) and make a small dummy ISO in the first partition of the same name (see ‘choose an ISO from ptn2’ above for details).

5. Boot to the E2B drive and run ‘True Hide (hd0,0)’ to hide partition 1. 
You should now be able to boot to the E2B Windows menu, pick an ISO and then install from it. You can also use a .mnu file (see above). 
Partition 1:
\_ISO\WINDOWS\WIN10\Win10x64.iso (any non-zero size – any contents)
Partition 2:
\AutoUnattend.xml
\Unattend.xml
\_ISO\e2b\firadisk folder
\_ISO\WINDOWS\WIN10 folder + \_ISO\WINDOWS\WIN10\Win10x64.iso  (5GB) 

Note: SDI_CHOCO is not supported if the E2B partition is hidden, because Windows will not be able to find the SDI_CHOCO configuration files later on!