Create clean Legacy+UEFI bootable drives without Rufus - Instructions

Someone brought this to my attention, it works great.  Thanks @DoubleDD 

How to make 100% compatible Legacy + UEFI bootable USB. (This software has not been updated since 2013, its working but you must follow directions exactly for expected result..)

You can find this software elsewhere but for some reason they make it a pain with a password.  Google search for the filename below to download directly from the authors site...

Or get it here - UEFI_MULTI_85.EXE https://mega.nz/#!tiRXiSwD!hdty2YSe8EUOV51_n8D574whnXg8FYkFxxXvDuquhYU

This is actually faster than the Rufus method too, just a little more effort ;)

1.) Extract the UEFI_MULTI_85.exe by double clicking it (It extracts to same folder)

2.) Mount your WinPE ISO or extract your WinPE ISO to its own folder on your desktop

3.) Plug in your USB

4.) In the folder you extracted UEFI_MULTI_85.exe to, Run UFD_FORMAT.EXE. Leave the
1st Partition set to FAT32, Check the checkbox for a 2nd partition.  Pick MAX for 2nd
partition NTFS size. This creates a minimal 2gb fat32 Partition to hold the wim and
bootfiles. (YOU CAN CHANGE THE 2nd PARTITION TO 75% or 50% etc to increase the FAT32 size so the
WIM fits as needed.)  I highly recommend keeping the 2nd partition as LARGE as possible.  Also
UNcheck "Make boot menu". Select your USB by clicking the button with the "..." on it, and
then click "Format Stick".  When finished, -->RENAME<-- THE  2gb FAT32 UEFI_BOOT partition
to "BOOTFILES" and the other NTFS partition to Win10PEx64 (Sometimes you will have to
manually format the second NTFS partition.  If so, to do this either double click the
partition in explorer, and click format, or, right click it and select format, Make sure to
select NTFS and quick, and set the volume label to Win10PEx64)

5.) In the folder you extracted UEFI_MULTI_85.exe to, Run UEFI_MULTI.EXE
Select the BOOTFILES partition as the "Boot Drive" AND "System Drive" in the USB
target section via the "..." buttons (Otherwise the program crashes) Then go up to
the sources section at the very top field (Which is no longer greyed out after the
target section is completed) and from there use the "..." button and browse to the
folder on the desktop you extracted your ISO to.  Inside that folder select
Sources>boot.wim.  Next the program will tell you that you need to find the boot.sdi
that came with the ISO.  Navigate back to the same extracted ISO folder on the
desktop and instead of sources go into Boot>Boot.sdi and select that. Then click GO

6.) Then navigate to the root of the new BOOTFILES partition and DELETE the below
files.

grldr
grldr.mbr
menu.lst

7.) Then copy the below FILES\FOLDERS from the ISO to the root of the
Win10PEx64 NTFS Partition you made at the end of step #4

Programs
autorun.ico
CDUsb.Y
Win10PE.cd
pecmdExt.ini  **if present


************************************************************************************
For this method YOU WILL NOT NEED THE BELOW FILES\FOLDERS from the ISO, they are
only needed if you use the Rufus method. Do NOT copy these to your USB)

Boot
efi
sources
BOOTMGR
bootmgr.efi
bootmgr.exe

************************************************************************************

8.) Download and install EasyBCD from here: https://www.freewarefiles.com/EasyBCD_program_21892.html
 
(You may need to manually type the below paths in the EasyBCD "open file" window because they are hidden)

  In EasyBCD select File>Select BCD Store (for the Legacy BCD)

For Legacy BCD Navigate to the root of the BOOTFILES partition.  In the BOOT folderselect the file named BCD. Then click the "Edit Boot Menu" button.  On the right side
set the boot-wim entry to default by checking the checkbox, and select the
"Skip the Boot Menu" radio button then click "Save".

  Then select File>Select BCD Store (This time for the UEFI BCD)

The UEFI BCD is located at BOOTFILES partition.  In the EFI\Microsoft\Boot folder
select the file named BCD.  Repeat the above process by selecting boot-wim as default
by checking the checkbox and selecting the "Skip the boot menu" radio button then
click "Save"

----------------------------

Now you will have a CLEAN bootable USB for any system Legacy/CSM or UEFI....

(*NOTE: You can rename the partitions to whatever you want, I only used specific names to keep the directions simple and easy to follow.)

This is excellent.  Can't believe you've got no replies.  Only slightly confusing part was in step 5, it wasn't clear on initial read if I had to select anything for the source folder.   You say, "in the sources section" [...] choose the boot.wim.  Should add something in there about the "in the sources section, click the '...' button for the boot image.  leave source folder blank."  Otherwise worked flawlessly.  Thanks!

If you use CdUsb.Y in your projects and are on a Win10 Host, try this: http://theoven.org/index.php?topic=2506.0