Booting Boot Camp externally (if don't have enough internal space, or don't want...
 
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Booting Boot Camp externally (if don't have enough internal space, or don't want to turn off FileVault and repartition)  

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yjchua
(@yjchua)
Eminent Member
Joined: 5 years ago
 

Hi,

I posted these steps on Macrumors before, but here it is again if anyone needs to boot Windows off an external drive for whatever reason (off a Mac).

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.

[Please login to see this]

Take note of the disk you want to select

[Please login to see this]

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:

[Please login to see this]

Restart your entire Mac. After the chime, hold down Option and when prompted to select your boot drive, select EFI Boot (or whatever else that comes up for a BIOS-CSM installation).

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 Smile

Don’t use a USB stick.

Note: This method involves reformatting the entire external drive.

For Thunderbolt drives, just boot from the Windows USB installer and install directly onto the TB drive. Windows sees TB drives as an internal PCIe connection. However, you must format the TB drive as GPT first. 

CAUTION: Windows can only be installed in UEFI flawlessly on Haswell Macs and later. Ivy Bridge and earlier Macs can only run Windows in BIOS-CSM flawlessly. Attempts to boot a UEFI installation of Windows on an Ivy Bridge or earlier Mac will result in driver issues.

These steps do not work with Windows 7, as it lacks the dism.exe utility.

UEFI-compatible Macs:

Long story short, only Macs with PCIe SSDs support UEFI. Non-retina MBPs, along with other Macs not listed above (basically all Ivy Bridge and older Macs), are not UEFI compatible.

Late-2016 15" rMBP (2.9/16/1TB/460)
Akitio Node + Asus Expedition RX 570 OC, 4GB

 
2018 Mac Mini [8th,6C,B] + RX 570 @ 32Gbps-TB3 (Razer Core X) + macOS 10.14 & Win10 [build link]  


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itsage
(@itsage)
Founder Admin
Joined: 5 years ago
 

@yjchua thank you for the instructions! I edited the layout to distinguish the cmd codes vs. text content.

I'm sure many of us will need to use an external drive for gaming in Windows with a Mac. What are thoughts on installing an external drive through an eGPU enclosure? A few of us are testing this Thunderbolt 3 boards from Mantiz which has a SATA connector.

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yjchua
(@yjchua)
Eminent Member
Joined: 5 years ago
 
Posted by: itsage

 

@yjchua thank you for the instructions! I edited the layout to distinguish the cmd codes vs. text content.

I'm sure many of us will need to use an external drive for gaming in Windows with a Mac. What are thoughts on installing an external drive through an eGPU enclosure? A few of us are testing this Thunderbolt 3 boards from Mantiz which has a SATA connector.

   

Sorry for the late reply haha (been really busy ever since I got back to Melbourne)

For the type of setup that you mentioned above, just booting off a Windows USB installer stick will do (no need to mess around with CMD and those stuff), because Windows will see such drives as being connected via an internal PCIe bus.

Whether or not the bandwidth will be affected due to both hard drive and GPU sharing the same Thunderbolt interface, I wouldn't know.

 

Late-2016 15" rMBP (2.9/16/1TB/460)
Akitio Node + Asus Expedition RX 570 OC, 4GB

 
2018 Mac Mini [8th,6C,B] + RX 570 @ 32Gbps-TB3 (Razer Core X) + macOS 10.14 & Win10 [build link]  


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Osa
 Osa
(@osa)
New Member
Joined: 4 years ago
 

@yjchua 

 

Thank you for the topic.

This is the only installation method that I found where it addressees the drivers issue and using BIOS-CSM installation in specific. I followed all the steps, until I rebooted my mac but I got this error: 

RECOVERY

Your PC/Device needs to be repaired. 

The application or operating system couldn't be loaded because a required file is missing or contains errors. 

File: \Windows\system32\winload.efi

Error code: 0x000000e

You'll need to use recovery tools....... etc

I repeated the steps twice just in case I made an error but still the same issue. 

I installed reFind to manually choose the legacy boot but once I choose it, I get this message:

No bootable device -- insert boot disk and press any key

 

Other information:

- MacBook Pro 13" late 2011 (8,1) using Sierra as an operating system.

- I'm trying to install Windows 10 on a secondary internal hybrid drive that's installed on the optical drive place.

- Before  I followed your method, I used bootcamp to install windows on the hybrid drive (I changed info.plist manually to trick bootcamp) - Windows was installed successfully but with drives issues. So my main SSD already have an EFI folder with Microsoft stuff from the original bootcamp install (not sure if I'm suppose to delete them?)

- The way that I formatted the hybird drive was through an external hard drive that already had windows 10 installed using Rufus (has drive issues). 

 

I been struggling with this for few days because of the drive issues. I hope you can help and I'd really appreciate it any tips!

 

To do: Create my signature with system and expected eGPU configuration information to give context to my posts. I have no builds.

.

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