Bootable External USB HDD - UEFI & Legacy?

Discussion in 'PC Hardware' started by IAmTheDude, Feb 11, 2016.

  1. IAmTheDude

    IAmTheDude MDL Member

    Oct 12, 2011
    Hey all,

    Quick one hopefully.

    Ive got a 500GB external HDD that I created to run a multitude of recovery wims and OS installs to run from.

    It boots to the Windows Boot Menu (BCD) and I can select which wim to boot from. The main 128GB partition is FAT32 and all the OS wims are .swm to fit on for FAT32 and be UEFI compatible.

    The main wims I use are custom W10 WinRE's (x86 & x64).

    This all works fine using the normal 'Legacy' boot mode, by turning off SecureBoot and chaging to CSM but I am having difficulties getting it running in UEFI.

    I've followed a multitude of tutorials but still coming up short.

    Closet I've got is a BSOD stating winload.exe is broken or something to that extent. So I'm getting somewhere.

    I dont have a UEFI PC myself but have one here to play with, so:

    Q1: Is it possible to have both Legacy and UEFI boot on the same drive?
    Q2: How?

    Would appreciate any help as this is the last stage of finishing up my drive!

    Thanks in advance!
  2. 100

    100 MDL Expert

    May 17, 2011
    Error code would help. If it's 0xc0000428 (STATUS_INVALID_IMAGE_HASH) my guess is that you're trying to boot a newer OS using an older version of the boot manager (bootmgr.exe/bootmgfw.efi) that can't verify the signature of winload.exe/winload.efi.
  3. IAmTheDude

    IAmTheDude MDL Member

    Oct 12, 2011
    #3 IAmTheDude, Feb 15, 2016
    Last edited: Feb 15, 2016
    Sorry for the late reply, I left the UEFI lappy I'm playing with in the office for the weekend.

    The HDD boots straight to a blue screen with the error code 0x0000225 and \windows\system32\winload.efi.

    So it looks like 'somethings' working for it to be seeing something UEFI but a bit lost from here.

    This occurs with or without Secure Boot enabled (don't expect it to work anyway with it on!)

    Ill do some digging today but am not uptodate on the UEFI side of things as Ive never had one.

    ;edit; Just to add as well, now its showing up in the UEFI boot devices selection menu whereas before it wouldn't so Im assuming I have the other UEFI stuff sorted on it like FAT32 and it being 'bootable' etc