Creating Dual Boot USB (Like Win10)

Discussion in 'Windows 10' started by IAmTheDude, Sep 7, 2015.

  1. IAmTheDude

    IAmTheDude MDL Member

    Oct 12, 2011
    Hey all!

    So, Ive got a nice x86/x64 dual booting Win10 USB thanks to the MS Media Creator Tool.

    How do I go about doing this for 8? And 7?

    I have never touched this side of things so dont know where to begin.

    I did try copying the x86/x64 folders to the Win10 USB which seemed to work but obviously said 'Windows 10 Setup'. Didint try a full install with it though.

    I use both x86 & x64 systems which is a pain but the way it works with 10 is brill and hoping to get that down from six USB sticks to three!

    I know there's other ways such as E2B etc but I rather like the minimalist approach of the default 'Windows' way plus if I can do a version for a friend that is not so tech savvy but savvy enough to install Windows (if that makes sense, E2B would baffle him...)

    Where do I start?

    Cheers :)
  2. IAmTheDude

    IAmTheDude MDL Member

    Oct 12, 2011
    #3 IAmTheDude, Sep 8, 2015
    Last edited: Sep 8, 2015
    I did think of doing it this way but I have some stuff going off with $OEM$ and Setupcomplete.cmd that are OS specific along with some auto-installs on first boot, per OS.

    I found something called the BCD which seems to be what Im looking for though.

    So far Ive been able to get the menu to display how I want it just gotta figure out the rest.


    In the root of the USB I have the boot files from the W10 USB which points to /x86/sources/ and /x64/sources.

    What Im aiming for is folders like:




    With each menu option pointing to the relevant folder.

    Having it set like this means I can have $OEM$ doing its business as normal and also if I make changes to boot/install.wim its a small matter of just replacing it rather than having to do a full export etc

    I know you can do some funky stuff like having a sinlge wim with dual archs with one set
    of setup files etc ut this way is closer to having a "single" USB for each OS which I find easier to manage (still quite new to this side of things.)

    If I can get this working I could also just have one 64GB USB with everything on it easily as well and all that would change is the BCD menu.

    Cant seem to find much regarding the BCD in relation to anything other than the system one.
  3. IAmTheDude

    IAmTheDude MDL Member

    Oct 12, 2011
    OK, so, did some reading.

    From what I can make out, bootmgr is hard coded to read from xx:/boot/boot.wim and xx:/sources/install.wim

    If either of these paths are changed it will boot the setup files rut then I run into errors with the install. Mainly "Missing Media Driver" errors.

    Using the W10 dual boot files I can replace the contents of the x86 and x64 folders, edit the BCD menu to say "Windows xx Setup" and it will work fine.

    However if I change the paths in the BCD I immediately get "Missing Media Driver" errors in the setup.

    So, it is possible to get one USB for each Windows version with dual-arch and in a way I can keep the $OEM$ working.

    What I havnt een able to do is get the default Windows bootmgr to have a menu with multiple OS's.

    I have had a play about with others like grub but it was 'too much' for a simple thing and then theres the UEFI business to mess around with as well so thats a no-go.

    What I have decided to have a play with is using a WinPE.

    Boots into the PE, has shortcuts to the setup.exe for each OS on the desktop and install the OS from there.

    Ive had a custom disc like this before many moons ago which had the option to boot into the WinPE or boot into the normal Windows setup.

    Some questions no doubt to come...
  4. IAmTheDude

    IAmTheDude MDL Member

    Oct 12, 2011

    Went the WinPE root and sorted it well and good :)

    Full answer here save me duplicating it.