[GUIDE] How to install windows 10 bootcamp on an external hdd or ssd
A lot Can be said about installing windows 10 bootcamp on an external hdd or ssd to save some precious space on the macbook ssd. After trying a lot of not so well discriped (failing) guides i came across this excellent guide made by Simphax from here. It works excellent on all efi supported macbooks.
What you will need is either a working windows 10 installation or create one in a virtual machine like in VMWare fusion (free edition will work) or parallels. Windows 10 ADK as decribed below and ofcourse a windows 10 iso.
Process for 2015- MacBooks (EFI installation)
In Mac OS:
- Run Boot Camp Assistant to put the Windows drivers onto a separate USB stick
- Download a Windows 10 x64 ISO
- Transfer the ISO to your Windows installation.
- Install Windows ADK, uncheck all alternatives except "Deployment Tools"
- Double click the Windows ISO to mount it as a drive
- Plug in the external USB drive.
- Open command prompt and run the following:
Formatting the drive:
diskpart list disk select disk 1 (the id of your external drive) clean (warning: this will erase everything on the drive) convert gpt create partition efi size=200 format quick fs=fat32 assign letter=s create partition msr size=16 create partition primary format quick fs=ntfs assign letter=w exit
dism /apply-image /imagefile:D:\sources\install.wim /index:1 /ApplyDir:W:\ /CheckIntegrity
where D is the letter of the windows installation drive, W is the external drive's NTFS partition, Index "1" is for Windows 10 Pro, use "2" for Windows 10 Home)
Installing boot files:
bcdboot W:\Windows /s S: /f UEFI (S is the external drive EFI boot partition)
Done! Plug the drive into your Mac and restart holding down the Option key and you should see EFI Boot as an alternative, this is your Windows 10 installation.
Final step is to install the Boot Camp Windows drivers. Run setup.exe from the USB drive.
I hope this is of use and service to all of you.
An alternative method, especially useful if you want to migrate an existing Windows installation:
- Install or migrate your existing Windows installation into a VMWare Fusion virtual machine.
- Boot the Acronis Backup and Recovery bootable ISO in Fusion.
- Create backup of the whole virtual Windows volume.
- Restore backup to the USB disk, attached to the virtual machine.
Don't forget to activate USB 3.0 support in the Fusion USB settings of the virtual machine to speed up things.
Hi, I've tried your first suggested method. Everything works fine until I get to the booting part. The mac just wont see the SSD drive so I could start the Windows installation. I've also tried other methods leading to the same problem.
Do you have any idea what is wrong ?
Do you already have BootCamp installed on your internal drive? In that case, the drive won't show. I had same issue, deleting bootcamp partition on your internal drive solve the problem.
Hi, thanks a lot for the video. I already tried 3 other complicated methods of installing Win on my external SSD with the same issue, of not seeing the EFI at boot time. But with your solution it worked.
I was the original creator of the steps for creating an external Boot Camp partition.
Original post: https://forums.macrumors.com/threads/bootcamp-windows-10-from-external-drive.1815672/page-3#post-20758398 (posted in February 2015) - way before Simphax's and Orkoden's answers (which were most likely ripped off my original post on MacRumors.)
I can safely say that to this day, my method still works well as it has separate steps for UEFI and BIOS-MBR systems (see the later pages of the MR thread).
Original thread regarding external Boot Camp on egpu.io: https://egpu.io/forums/mac-setup/probably-off-topic-booting-boot-camp-externally-for-those-who-dont-have-enough-internal-space-or-for-those-who-dont-want-to-turn-off-filevault-and-repartition/
My Win 10 (Creators) VM on parallels can't detect my external SSD and connecting it as a USB device directly, instead, it connects it as a network drive from Mac, therefore, diskpart won't detect it, although I modified parallels settings for connected USB devices in general and this external SSD in particular.
my external SSD is Raid SSD (NTFS) connected via TB3 interface.
is there anything I'm missing in this guide?
Mohammad Katayen (mklegend)
I also highly recommend installing rEFInd! http://www.rodsbooks.com/refind/
It's an EFI Boot Manager. Let's you install Windows, MacOS, Linux and etc.
ex-AKiTiO Employee as of August 2018.
If it's connected via TB3, you don't need any of these steps. You can just boot from a Windows USB installer and install directly to the TB3 drive, because Windows will see it as an internal drive.