Bootcamp Windows 10 from External Drive?

Discussion in 'Windows, Linux & Others on the Mac' started by bmac89, Nov 6, 2014.

  1. bergui45 macrumors newbie


    Oct 5, 2008
    I can run Win10 on VMWare Fusion 7 but when i try to run WintoUSB it only let me write to a USB flash of 40 MB and not the whole size of the stick of 32 Gigas!? I don't want to pay for the commercial version at 35€...
    I may also want to back pedal to WIN7 Pro since i no more want Microsoft spy my system and brutally FORCE the windows update process.
    Maybe also i had to go MBR instead of GPT on the Thunderbolt drive to get a more stable behavior...
  2. bergui45 macrumors newbie


    Oct 5, 2008
    Hello ychua95,

    You are a very well knowledgeable guy! wahouh!
    I now thanx to this post, can understand why i have some issues with my Windows 10 installed on a HighPoint Rocketstor 5212 dock on my mid 2012 MBPro15".
    This "old laptop" is an IVY BRIDGE so it could only run Windows in MBR!
    You said:Attempts to boot a UEFI installation of Windows on an Ivy Bridge or earlier Mac will result in driver issues.

    I Confirm: Windows 10 Boots on EFI/GPT but there is 2 driver issues:
    NO SOUND and the HD 4000 Video doesn't work but only the NVIDIA...


    Let me know should i redo the whole process from scratch or is it possible to simply convert my GPT disk to MBR without losing any data?
  3. bergui45 macrumors newbie


    Oct 5, 2008
    Hi folks,
    I'm glad since i could redo the Windows10 MBR installation with the simplest way to have success!
    I only used the Bootcamp assistant tool within El Capitan to make a USB stick installer with the Win 10 Threshold2 ISO.
    Then i opened my MBPro mid 2012 "Ivy Bridge" in order to disconnect both the SSD in the optical bay and the HDD.
    After reboot from the USB stick the installation on the SSD docked in the HighPoint Rocketstor 5212 went flawlessly.
    After a successful first boot of Windows i installed the Bootcamp drivers!
    Now everything's fine and Windows boots VERY VERY FAST in less than 15"!
    Thanx again to ychua95 for the warning about EFI/Boot on this Ivy Bridge, that was a very bad trip!
  4. bergui45 macrumors newbie


    Oct 5, 2008
    It's easy to do it without any Linux or Windows USB stick!
    Use Bootcamp assistant inside EL Capitan + an ISO of Windows 10!
    Bootcamp Assistant will create an USB stick installer.
    Have your external SSD already formatted Fat32
    Then open your Mac and disconnect your internal drive. then Boot with the USB stick and Windows will install without any hiccup! I've had success on a mid 2012 MBPro 15" (Ivy Bridge) on a Thunderbolt dock + SSD Transcend 128...
  5. maflynn Moderator


    Staff Member

    May 3, 2009
    I used this method yesterday after trying and failing to use WinToUSB, for some reason it just didn't like the partition on my SSD to install the OS on. Anyways long story short, I have windows running on an external drive. Its working well, and as to be expected faster then my bootcamp partition. I have a Fusion drive, so Windows is running on the spinning hard drive, as opposed to this version chugging on a SSD.

    No matter how many times I may install windows, each time I do, the results are different, just little things I find out from one install to another, and then forget. So my bootcamp partition has some nice refinements that I forgot how I did it. I'll eventually google them and try to repeat.

    Odd thing, is I didn't have to activate this version, Perhaps when it phoned home, it saw that it was the same iMac (though different drive). I dunno, but kudos to yjchua95 to providing the steps.

    I'm not sure which version, I'll keep, I've been using that external drive for different operating systems, and when Redstone hits later this summer, will upgrading that be smoother on this, or the bootcamp partition (or will it matter)?
  6. NazgulRR macrumors 6502

    Oct 4, 2010
    Has anyone been able to apply the 1607 (anniversary edition) upgrade to their Windows 10 on external SSDs?

    I keep getting the Windows 10 couldn't be installed / You can't install Windows on a USB flash drive using Set-up. And it's not even a USB flash drive, but a Samsungs 840 Pro SSD... :S
  7. maflynn Moderator


    Staff Member

    May 3, 2009
    Try using these steps. Because Windows is on a USB device, you cannot just upgrade it normally

  8. Traverse macrumors 603


    Mar 11, 2013

    I'm about to do this to install W10 on an external drive because I need boot camp performance, but my internal drive is full.

    Once you install W10, do you boot back to OS X to get the boot camp drivers and then boot back into Windows to install them?
  9. Gjwilly macrumors 68030

    May 1, 2011
    SF Bay Area
    You can but you can also just download them to a USB drive in advance.
  10. NazgulRR macrumors 6502

    Oct 4, 2010
    Well, that's the method that I have used to install the Windows (1511 version) in the first place.

    Are you saying that this particular update is not possible through the system update and that one needs a complete format and clean install?
  11. Gjwilly macrumors 68030

    May 1, 2011
    SF Bay Area
    Are you getting the AE from the normal Windows Update or did you download the standalone installer?
  12. NazgulRR macrumors 6502

    Oct 4, 2010
    The normal Windows update.
  13. evangw macrumors regular

    Feb 9, 2008
    Thanks yjchua95, you're awesome. I followed your instructions and it worked great. I could not find similar instructions for UEFI installations anywhere on the Internet, and I probably searched for 3 hours before finally winding up at a new thread in the MacRumors forum for the tenth time.
  14. Gjwilly macrumors 68030

    May 1, 2011
    SF Bay Area
    I just tried Windows Update and AE still hasn't rolled out for my installation. It just kept saying I was up to date.
    I clicked the link about looking for latest versions and it took me to the standalone AE installer.
    That one installed without any errors.
    My Windows is on a USB-3 SSD originally created with yjchua95's method.
    My mac is the 2013 rMBP.
  15. bergui45 macrumors newbie


    Oct 5, 2008
    My Win10 (mbr) on my mid 2012 MBPro 15" boots flawlessly on the Thunderbolt SSD but to have success i had previously to disconnect both my internal (SSD +HD) drives. OK when i installed Windows i had my internal disks disconnected to prevent Windows making crap on one of these disks.
    The Thunderbolt SSD is seen like an inner dik 0 but things may be different when the Thunderbolt drive is connected to the Mac with the inner diks already connected. i guess i had to modify the BCD boot file but i don't know where it is?
    Thank you for a tip
  16. GTi3993, Oct 2, 2016
    Last edited: Oct 2, 2016

    GTi3993 macrumors newbie

    Sep 7, 2011
    Install Windows on External Hard Disk and Boot From Mac .
    Without Boot Camp

    Start From Scratch & Please Follow Step By Step
    For the best use of these steps , i suggest you google each one before you start !! aka gather some info

    Hardware Requirements :-
    1. ANY Windows Operating system Computer installed and working .
    2. Obviously a Mac computer with OS X10.10 and above
    3. External Hard-Disk 32 Gb or More .(where you will install Windows)
    4. 4GB USB Key .

    Software Requirements :-
    • Files To Download On Windows
    1. MediaCreationTool.exe (LINK) .
    2. Windows.iso x64bit downloaded by the tool above and saved to your PC.
    3. WinToUSB Enterprise v3.2 Multilingual Portable (just google that)
    • Files To Download On Mac
    1. gdisk-1.0.1.pkg (LINK)

    On WINDOWS :

    1. Open MediaCreationTool
    3. Choose language and edition but it must be 64-bit
    4. Save to ISO file ON YOUR PC ( Over 3 GB to download so you can follow with the next steps you still have sometime ! ) .
    5. Plug in your External Hard-Disk (where you wish to install Windows.)
    6. ON keyboard press and hold Window sign and the letter R (will open Run)
    7. Type DISKPART (now it will open a cmd) next steps in cmd
    8. Type list disk
    9. Type select disk # (replace # with your external hard disk number that you got from the step above)
    10. Type clean (when done you can close)
    11. Right Click on your computer icon and select Manage.
    12. On the left panel click on DISK MANAGEMENT "will take sometime to show also if it tells you to initialize choose gpt "
    13. Find your external hard disk
    14. On the DISK number right click and convert to gpt
    15. now on the free space create a first partition with 500 MB and format to FAT32 name it EFI
    16. Format the the rest of the free space to NTFS and name it OS
    17. when done close everything you opened (clear view to desktop) .
    18. Open WinToUSB Enterprise with administrator privileges.
    19. Choose the WINDOWS.ISO (if MediaCreationTool done with downloading the iso)
    20. Choose the External hard disk you just formatted .(must see and choose EFI if you did not see it that means you didnt format the hard disk or maybe still no converted to gpt google around)
    21. Choose your desired Operating System.
    22. Install and wait until its Done.

    On MAC :

    1. Open boot Camp app from your mac
    2. Choose only to download latest media "basically uncheck all but check the second option ".
    3. Save it to the USB KEY (Mentioned in Hardware Requirements above) .
    4. This will download windows boot camp divers for your windows computer.
    5. Unplug USB KEY when done.
    6. Open the file gdisk-1.0.1.pkg and install (Mentioned in Software Requirements above) .
    7. Plug in your external HARD DISK .
    8. Open terminal and run these commands and dont try to be geeky just follow these commands.
    9. Type sudo gdisk /dev/disk0
    10. Type p to view the existing partition table and verify you’re working on the correct disk.
    11. Type x to enter the expert menu.
    12. Type n to create a fresh protective MBR
    13. Type w to save your changes and confirm the changes.
    14. Type q to exit GPT fdisk.
    15. So basically p enter x Enter n Enter w Enter q Enter .
    16. Now restart and hold the option key and choose the External Harddisk
    17. it Might boot several times make sure you always hold the option key .
    18. When setting up Windows 10 is done plug in your USB key and install bootcamp drivers.
    19. Done :)
  17. lq_sunshine macrumors newbie

    Oct 25, 2016
    Many Thanks for all the helpfull instructions.

    I have another question:

    is it possible to use the external windows Hard Drive as an internal drive?

    e.g. open the case of the external drive, take out the hard disk and put it into the imac as main drive?
    Has someone tried it?
    It would be interesting when the internal drive is damaged.

    thank you

  18. ross1999 macrumors newbie


    Nov 3, 2016
    thanks, i was looking all day for a way to do that. is there a workable how to do install win10 on ext.hdd to run on mbp retina 12/2012? I looked for and tried 5 but it did not work. i dwnld already win10 pro iso, bootcamp drive.
    Many thanks,

    How to Run a Portable Version of Windows from a USB Drive a
  19. ross1999 macrumors newbie


    Nov 3, 2016
  20. bergui45 macrumors newbie


    Oct 5, 2008
    I'm still waiting for a tip on modifying the BCD boot loader file since with all disks connected the external SSD is no more disk0 but disk4...
  21. bergui45 macrumors newbie


    Oct 5, 2008
    Let me know you get success with an UEFI windows installation on your Mac mini and MBA?
    I was told that the MBPro 15" mid 2012 with Ivy Bridge cannot let you instal WIN10 UEFI but MBR only...?
    Of course i had success with an UEFI installation but Windows never performs normally and many drivers errors occured.
    Since i have done it with MBR it's rockstable! The only drawback is i only can run Windows after disconnecting my internal MacOS disks because i made the windows installation this way so my external SSD docked in a Thunderbolt bay is blessed as disk0.
    Should i reconnect my internal drives at startup while pressing option key, i can see the windows external SSD disk with the same icon than an internal HD, (it was different in EFIboot previously) but Windows doesn't boot with the blinking --!
    Paragon techee said that the Mac boots in EFI mode and that's the reason why it messes to boot Windows because the Windows MBR boot loader is different? Holy crap!
  22. bergui45 macrumors newbie


    Oct 5, 2008
    Wahouh GTi3993 wrote a fantastic step by step "stairway to heaven"!
    I will try it since this solution is a mix of EFI & MBR.
    Is there an easy way to convert my MBR formatted SSD to GPT without loosing data instead of making the whole thing from scratch?
    Should i have my working MBR windows saved may i restore it in the new MBR partition?
  23. out.of.order macrumors newbie

    Sep 17, 2013
    What advantage does it have to put Windows on an external disk???
    To use it you always have to remind yourself to take it with you.

    I just installed Windows 10 Pro natively on the same disk together with MacOS
    in mode GPT and works much better than with Bootcamp.
    My computer is last MacBook Pro TB 13" 2016.

    I have split disc in 3 parts.

    One for MacOS
    Another for data 300GB NTFS
    And at the end of the disc one partition for Windows.


    And external disk I use to have save more files
    if I forgot at home this disc, nothing happens
    because the system I have on internal disk.

    For this reason if someone can tell me please what advantages has
    Windows installed on external disk?

  24. Huntn macrumors G5


    May 5, 2008
    The Misty Mountains
    I'm within a week of taking receipt of a 2016 MacBookPro 13" (release Oct 2016) and on my last 3 or 4 Macs I've done the Bootcamp route to get Windows running on my Mac. I'm seriously thinking about trying to install Windows 10 on an external 2TB drive without partitioning my Mac's HD and am wondering how easy this is? I admit I've not looked back over all the pages of this thread. :oops:

    I'd like to ask, if I were to install 64bit Windows on this external USB drive, using my PC, would my Mac be able to see it without doing anything special to my Mac?

    I know there is an issue with using FAT32 vs NTFS. Can you describe what the 500MB FAT32 partition does. I assume the Mac an interact with it, but according to the instructions above, what about the other partition using NTFS?

    I do realize I'd have to go through the step of installing bootcamp drivers, which I've done before by simply running the driver program I downloaded via Bootcamp.

    What does gdisk do to your Mac?

    I mentioned @antonis because we recently discussed this in the 2016 MacBook Pro for Gaming Thread. :)
  25. maflynn Moderator


    Staff Member

    May 3, 2009
    This thread is 8 pages long, I can safely say installing Windows on an external drive is more complicated then it ought to be.

    For one thing, Windows by itself will not permit you to install on a USB drive, I'm not sure if you use a TB drive, it changes the equation.

    I successfully installed windows 10 on external drive but I could not upgrade it to the anniversary edition, there's steps needed to basically install a windows to go installation of windows 10. Its possible to do, and I used these steps:

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