Startup Manager: Windows and EFI Boot, remove EFI Boot

Hrhnick

macrumors member
Original poster
Jan 4, 2013
78
5
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?
 

yjchua95

macrumors 604
Apr 23, 2011
6,725
231
GVA, KUL, MEL (current), ZQN
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?
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 :)
 

Hrhnick

macrumors member
Original poster
Jan 4, 2013
78
5
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 :)

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...
 

yjchua95

macrumors 604
Apr 23, 2011
6,725
231
GVA, KUL, MEL (current), ZQN
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...
Nope.

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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