Startup Manager: Windows and EFI Boot, remove EFI Boot

Discussion in 'Windows, Linux & Others on the Mac' started by Hrhnick, Jan 18, 2015.

  1. Hrhnick macrumors member

    Jan 4, 2013
    So I followed this excellent guide to install Windows 8.1 to my external USB 3 drive. It works great and the SSD and USB 3 combo make it super fast and stable after installing the bootcamp drivers.

    Only issue, is cosmetic. When I option boot, I get two icons for the external drive, Windows and EFI Boot. The Windows partition boots as expected, but the EFI Boot does nothing. I just want to hide it. I tried deleting it, and the Windows partition then stopped working, so I know its needed.

    Can I hide the EFI Boot partition from the option Statup Manager?
  2. yjchua95 macrumors 604

    Apr 23, 2011
    GVA, KUL, MEL (current), ZQN
    I tried using that guide before but it failed on me big time. The guide over there only lets you install Windows in an emulated BIOS environment and not in a UEFI environment.

    So after some experimenting, I came up with my current method which works via UEFI really well. At the boot selection screen, only EFI Boot will show up. A native UEFI installation is always preferable.

    Here goes. It's easier and does not use imagex. Rather, it uses the built-in dism.exe utility.

    Connect external drive to Windows VM. You must have a Windows VM in VMware/Parallels/VBox, or a Windows PC. Any existing Windows environment will do.

    What you need:
    install.wim file (obtain this from your Windows ISO)

    Open elevated cmd.exe (run as admin)

    Note: All commands aren't case sensitive, including pathway to files.

    Type diskpart
    Type list disk
    Take note of the disk you want to select
    Type select disk 1 (if your disk is Disk 1)
    Type clean
    Type convert gpt
    Type create partition EFI size=100
    Type format quick fs=fat32 label=EFI
    Type assign letter=S
    Type create partition primary
    Type format fs=ntfs quick label=W2G (or any other name you wish for label)
    Type assign letter=E
    Type exit

    Open up File Explorer. In your C drive, create a new folder named WIN2GO.
    Put the install.wim file in this folder

    Back in cmd.exe:
    Type dism /apply-image /imagefile:C:\WIN2GO\install.wim /index:1 /applydir:E:\ (this process will take quite a while)
    Type E:\Windows\System32\bcdboot E:\Windows /s S: /f UEFI

    Restart your entire Mac. After the chime, hold down Option and when prompted to select your boot drive, select EFI Boot.

    Proceed installation normally.

    After installation, install Boot Camp drivers. Feel free to trash the VM once you're done too.

    For best results, use USB 3/Thunderbolt. If you don't have USB 3, use Thunderbolt. If you have neither, stick back to the internal drive :)
  3. Hrhnick thread starter macrumors member

    Jan 4, 2013

    WOW Thanks!
    I originally wanted to do an EFI install but couldn't find a solid guide for EFI on an external drive. All the guides were external bios or internal EFI.

    I need a stable system for school this week, so I will hold off on the reinstall till next week.

    Is there anyway to rename the EFI Boot option to Windows? Just my OCD kicking in...
  4. yjchua95 macrumors 604

    Apr 23, 2011
    GVA, KUL, MEL (current), ZQN

    But it works well enough.

    You can also simply plug in the external drive into another Windows PC with a UEFI-compliant motherboard and it'll boot right up as well.

    I repurposed an old 7200rpm 500GB HDD for this and use it only for gaming.

    Meanwhile, I did the same for an external Transcend JetDrive 960GB SSD (but with a few additional steps for isolation, encryption and security, such as hiding the drive from a guest PC) so that it's more of an enterprise Windows to Go stick.

    That same SSD also contains a bootable OS X environment alongside the Windows partition. I had to install Windows first before repartitioning to install OS X.

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