Tips: How to make Windows 10 install media on macOS High Sierra

Posted:
in macOS edited December 2018
Apple stripped the ability to make Windows 10 install media from a flash drive or external SSD in Sierra, but sometimes, you still need to be able to do it from a Microsoft-provided download. AppleInsider shows you how to do it.




First, get the .ISO file from Microsoft here. Importantly, this doesn't contain a license code, so you'll need to get one of those yourself.

We implore you -- get the .ISO from Microsoft. Don't use a shady source.

Making a Windows 10 install disk from macOS High Sierra isn't as simple as formatting a drive in Disk Utility and copying over files in the Finder -- you need to use the Terminal. So, mount the disk you want to make install media, and open up the Terminal.




Find the name of the drive that you want to install the media on. Be sure that you've got this right -- because in later steps you can do massive damage to your boot drive if you're not careful.

Type diskutil list in the Terminal window to get a list of your drives. In our case here, it's "disk2." We'll use "disk2" going forward with this tip, but in the place of "disk2" use which disk identifier is appropriate for you.




Next, we'll format the disk in Terminal. Enter

diskutil eraseDisk ExFat "WINDOWS10" MBR disk2

This will format the drive suitable for a UEFI boot, name it "WINDOWS10," and mount it.




Your Windows 10 .ISO file download is probably in your Downloads folder. Mount the .ISO by double-clicking on it. It is probably called "CCCOMA_X64FRE_EN-US_DV9" but double-check.




A Finder copy doesn't work. In the Terminal enter:

cp -rp /Volumes/CCCOMA_X64FRE_EN-US_DV9/* /Volumes/WINDOWS10/




The Terminal will sit there for a minute, seemingly unfazed by your command. However, it is working, and after a period of time depending on the speed of your media it will complete unceremoniously -- but your data will be copied, and your media will be bootable.


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Comments

  • Reply 1 of 24
    dewmedewme Posts: 2,198member
    Thanks for the tip.

    By the way, I've been using the free (open source) cross platform Etcher app (etcher.io) quite a lot for doing bootable Linux installs from iso files on to USB and SD/microSD and it works like a charm. I've never tried it with Windows 10 installs but I expect it should work quite well. 
    edited January 2018
  • Reply 2 of 24
    Sadly, I had no luck using Etcher - it created the USB drive OK, but not in a format that would boot in a Windows machine.  And I did change all the BIOS settings as needed.
    Ultimately, I had to borrow a friend's PC to do create a bootable version.  Didn't have a chance to try the approach above.


    dewme
  • Reply 3 of 24
    It would be great if you could edit/start this article to clarify "why" you might need a bootable Windows 10 installer, vs. just the .ISO. Are we ultimately trying to use this for Bootcamp, or is this step required if you're just trying to set up a Virtual Machine i.e. VMware, VirtualBox, Parallels? Genuine question!
  • Reply 4 of 24
    dewmedewme Posts: 2,198member
    jdiamond said:
    Sadly, I had no luck using Etcher - it created the USB drive OK, but not in a format that would boot in a Windows machine.  And I did change all the BIOS settings as needed.
    Ultimately, I had to borrow a friend's PC to do create a bootable version.  Didn't have a chance to try the approach above.


    Thanks for giving it a try!
  • Reply 5 of 24
    Mike WuertheleMike Wuerthele Posts: 5,005administrator
    It would be great if you could edit/start this article to clarify "why" you might need a bootable Windows 10 installer, vs. just the .ISO. Are we ultimately trying to use this for Bootcamp, or is this step required if you're just trying to set up a Virtual Machine i.e. VMware, VirtualBox, Parallels? Genuine question!
    Bootcamp installs fine from an .ISO. Virtual machines generally do, but not always, so it might be helpful for that.

    It is probably of most use to a chronic troubleshooter, who has a running Mac and a dead Windows machine, and no good way to reinstall the OS. Or, if you just want to put the install media on a fast flash drive, instead of a DVD.
    edited January 2018
  • Reply 6 of 24
    I was under the impression that given what they did to BootCamp Assiatant, if one was running one of the Sierra's, one could NOT install win10 into a bootcamp created partition... hence the instructions to have the install files on a bootable external volume. So if I mount the ISO, run Bootcamp Assiatant, it will leave me with a win10 installation without needing the flash drive I created with your instructions?

    Thing is, I already have a bootcamp partition with what HAD been a functioning win10 install that "went" bad and leaves in a loop of trying to repair, not succeeding, trying again. Being a Mac guy, re-install the OS comes to mind... except I have no idea of I can actually do something like that without actually wiping out the whole install and starting from scratch. Open to suggestions...
  • Reply 7 of 24
    Mike WuertheleMike Wuerthele Posts: 5,005administrator
    paulcons said:
    I was under the impression that given what they did to BootCamp Assiatant, if one was running one of the Sierra's, one could NOT install win10 into a bootcamp created partition... hence the instructions to have the install files on a bootable external volume. So if I mount the ISO, run Bootcamp Assiatant, it will leave me with a win10 installation without needing the flash drive I created with your instructions?

    Thing is, I already have a bootcamp partition with what HAD been a functioning win10 install that "went" bad and leaves in a loop of trying to repair, not succeeding, trying again. Being a Mac guy, re-install the OS comes to mind... except I have no idea of I can actually do something like that without actually wiping out the whole install and starting from scratch. Open to suggestions...
    I just saw this comment -- yeah, you can boot from the Windows install media you made from your Mac here, and reinstall windows over your perpetually repairing partition. 
  • Reply 8 of 24
    jakesjakes Posts: 1unconfirmed, member
    If you add the v flag to cp -rpv /Volumes/CCCOMA_X64FRE_EN-US_DV9/* /Volumes/WINDOWS10/ you don't have to sit blindly and wonder if it doing anything.
  • Reply 9 of 24
    De DuckyDe Ducky Posts: 1unconfirmed, member
    ^^ I should have scrolled down! Sitting blindly waiting for it to finish...
  • Reply 10 of 24
    JSJS Posts: 1unconfirmed, member
    Hit Ctrl+T to see progress (per file)
  • Reply 11 of 24
    Got this error, cp: /Volumes/WINDOWS10/sources/install.wim: File too large I'm using a 16GB SD card which has plenty of space left on it. Resorting to using Rufus through Parallels
  • Reply 12 of 24
    Windows is throwing an error: "windows setup windows cannot open the required file C:\Sources\install.wim". The problem is that sources/install.wim is 4.4GB which is more than MS-DOS (FAT32) format can handle. I tried to format my disk to ExFAT instead but unfortunately my motherboard doesn't recognize that. Any ideas?
  • Reply 13 of 24
    iiGonZoiiGonZo Posts: 1unconfirmed, member
    cp: /Volumes/WINDOWS10/sources/install.wim: File too large im using a 16gb usb. did everything as it was listed. im trying to make a bootable usb with windows 10 on my mac to use on my brand new pc..
  • Reply 14 of 24
    jessemac said:
    Got this error, cp: /Volumes/WINDOWS10/sources/install.wim: File too large I'm using a 16GB SD card which has plenty of space left on it. Resorting to using Rufus through Parallels
    iiGonZo said:
    cp: /Volumes/WINDOWS10/sources/install.wim: File too large im using a 16gb usb. did everything as it was listed. im trying to make a bootable usb with windows 10 on my mac to use on my brand new pc..
    The instructions should say to use "ExFat" instead of "MS-DOS" format for the diskutil command:

    diskutil eraseDisk ExFat "WINDOWS10" MBR disk2

    The problem with MS-DOS format is that it has a max file size of 4GB, so obviously there's a problem when you try to copy the contents of the Windows 10 ISO because install.wim is larger than 4GB. This guide might have been written with an older version of Windows 10 in mind.

    I just ran through the process with ExFat instead of MS-DOS format and it seems to work fine.
    edited December 2018
  • Reply 15 of 24
    cataplinescataplines Posts: 1unconfirmed, member
    It didn't work, it said: cp: /Volumes/WINDOWS10/sources/install.wim: File too large
  • Reply 16 of 24
    Mike WuertheleMike Wuerthele Posts: 5,005administrator
    jessemac said:
    Got this error, cp: /Volumes/WINDOWS10/sources/install.wim: File too large I'm using a 16GB SD card which has plenty of space left on it. Resorting to using Rufus through Parallels
    iiGonZo said:
    cp: /Volumes/WINDOWS10/sources/install.wim: File too large im using a 16gb usb. did everything as it was listed. im trying to make a bootable usb with windows 10 on my mac to use on my brand new pc..
    The instructions should say to use "ExFat" instead of "MS-DOS" format for the diskutil command:

    diskutil eraseDisk ExFat "WINDOWS10" MBR disk2

    The problem with MS-DOS format is that it has a max file size of 4GB, so obviously there's a problem when you try to copy the contents of the Windows 10 ISO because install.wim is larger than 4GB. This guide might have been written with an older version of Windows 10 in mind.

    I just ran through the process with ExFat instead of MS-DOS format and it seems to work fine.
    hisryanness above has it right. We'll edit the text today.
  • Reply 17 of 24
    I mounted the .ISO before my USB. On the final step, when entering "cp -rp /Volumes/CCCOMA_X64FRE_EN-US_DV9/* /Volumes/WINDOWS10/", I receive the message "cp: directory /WINDOWS10 does not exist", despite the fact that both have been mounted. Is there any way around this and is it caused because I mounted them not in the order that you stated?
  • Reply 18 of 24
    Sorry, please ignore my previous comment, I have now resolved this issue, what must I do next now that I have this USB?
  • Reply 19 of 24
    This procedure doesn't work to me (of course bios is set to UEFI boot and the ISO has been downloaded directly from microsoft's)
  • Reply 20 of 24
    Mac Windows & Linux UserMac Windows & Linux User Posts: 1unconfirmed, member
    Jakes. Thanks for your tip on making the iso copy to flash drive with the v flag, because4 it is the flag for verbose mode which outputs what it is doing.
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