aussiec6
Level 1 (4 points)
Windows Software

Q: Boot Camp install will not go pass format

I have a late 2015 Mac 27". Have tried to install Boot Camp several times now - all failed. Problem arises when I get to the "format" phase of the partition on windows install. I select the Boot Camp partition and format it - then if I try to go to next it says "We couldn't create a new partition or locate an existing one". Spoken to Apple tech support and so far no resolution. Tried everything from new OSX install, to loading Boot Camp up and going through the same routine again.

 

At a lost - can someone help out?

iMac, OS X El Capitan (10.11.5), Late 2015 27" Retina

Posted on Jul 1, 2016 3:41 PM

by Loner T,Solvedanswer
Loner T Loner T
Level 7 (24,738 points)
Safari
A:

Apple Tech Support cannot find their own article.

 

Please see Boot Camp: "We couldn't create a new partition or locate an existing one" alert during Windows 8 install - Apple Support . This is valid on all 2015 or later machines for W8+/W10.

 

Do not connect any external storage to the iMac. Disconnect all hubs. Run the following two procedures

 

Reset the System Management Controller (SMC) on your Mac - Apple Support

How to Reset NVRAM on your Mac - Apple Support

 

Please remove the Bootcamp partition, if one was already created, and then re-try installing Windows via BC Assistant.

Posted on Jul 3, 2016 3:02 AM

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aussiec6

Q: Boot Camp install will not go pass format

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  • Helpful answers

  • by Loner T,Solvedanswer

    Loner T Loner T Jul 3, 2016 3:02 AM in response to aussiec6
    Level 7 (24,738 points)
    Safari
    Jul 3, 2016 3:02 AM in response to aussiec6

    Apple Tech Support cannot find their own article.

     

    Please see Boot Camp: "We couldn't create a new partition or locate an existing one" alert during Windows 8 install - Apple Support . This is valid on all 2015 or later machines for W8+/W10.

     

    Do not connect any external storage to the iMac. Disconnect all hubs. Run the following two procedures

     

    Reset the System Management Controller (SMC) on your Mac - Apple Support

    How to Reset NVRAM on your Mac - Apple Support

     

    Please remove the Bootcamp partition, if one was already created, and then re-try installing Windows via BC Assistant.

  • by aussiec6,

    aussiec6 aussiec6 Jul 3, 2016 3:12 AM in response to Loner T
    Level 1 (4 points)
    Windows Software
    Jul 3, 2016 3:12 AM in response to Loner T

    Thanks. Finally got a fix. Used Microsoft media creator to make a bootable windows 10 usb. The trick though is to get Boot Camp to download its software and partition the disk - but DO NOT let it auto start when it restarts the Mac. Hold the option key down on the Boot Camp restart (making sure the usb is plugged in) and then select EFI boot, which is the usb. This will install windows just like Boot Camp but when it comes to the formatting of the disk, the EFI usb installer works perfectly and formats the Book Camp partition (like Boot Camp should) and you can then select next and install windows.

     

    Why the folks at Apple haven't fixed this is a mystery. Apparently is an problem with late 2015 (and later) Macs.

  • by Loner T,Helpful

    Loner T Loner T Jul 3, 2016 12:12 PM in response to aussiec6
    Level 7 (24,738 points)
    Safari
    Jul 3, 2016 12:12 PM in response to aussiec6

    aussiec6 wrote:

     

    Thanks. Finally got a fix. Used Microsoft media creator to make a bootable windows 10 usb.

    The recommended method is to use an ISO.

     

    The trick though is to get Boot Camp to download its software and partition the disk - but DO NOT let it auto start when it restarts the Mac. Hold the option key down on the Boot Camp restart (making sure the usb is plugged in) and then select EFI boot, which is the usb. This will install windows just like Boot Camp but when it comes to the formatting of the disk, the EFI usb installer works perfectly and formats the Book Camp partition (like Boot Camp should) and you can then select next and install windows.

    The challenge here is repeating the Alt/Option hold method across 4+ reboots needed for Windows. If you use the Apple-documented method, this becomes unnecessary.

     

    Why the folks at Apple haven't fixed this is a mystery. Apparently is an problem with late 2015 (and later) Macs.

    2015 (and later) Macs do not need any external media to install Windows 8+/W10. It is documented in https://help.apple.com/bootcamp/assistant/6.0/#/bcmp173b3bf2 . If you choose to connect an external media, it causes the chain of events that you witnessed, and worked around.

     

    Glad to see it working. . Please back up OS X, Windows and create a Windows System Restore point.