Q: Error: "We couldn't create a new partition or locate and existing one" installing Windows 8.1 via Bootcamp

Hi

I am facing the same issue after 15 hours spent with Apple support and no luck.

I have attached the results of the above commands. My USB2 16Go flash stick was still connected when I ran them. I see two partitions in Disk Utility. The bootcamp partition of 360Go is formatted to NTFS (as shown as after the third command).

Does that sound right to you?

I bought this iMac two months ago. It has a 1TB Fusion drive. I managed to install windows very easily when I got the computer but had to delete the partition (used Bootcamp). Now trying to te-install windows.

Any help is extremely appreciated! Thank you!

Last login: Mon Mar  2 19:59:03 on console

charles-pc:~ Charles$ diskutil list

/dev/disk0

   #:                       TYPE NAME                    SIZE       IDENTIFIER

   0:      GUID_partition_scheme                        *121.3 GB   disk0

   1:                        EFI EFI                     209.7 MB   disk0s1

   2:          Apple_CoreStorage                         121.0 GB   disk0s2

   3:                 Apple_Boot Boot OS X               134.2 MB   disk0s3

/dev/disk1

   #:                       TYPE NAME                    SIZE       IDENTIFIER

   0:      GUID_partition_scheme                        *1.0 TB     disk1

   1:                        EFI EFI                     209.7 MB   disk1s1

   2:          Apple_CoreStorage                         638.9 GB   disk1s2

   3:                 Apple_Boot Recovery HD             650.1 MB   disk1s3

   4:       Microsoft Basic Data                         360.5 GB   disk1s4

/dev/disk2

   #:                       TYPE NAME                    SIZE       IDENTIFIER

   0:                  Apple_HFS Macintosh HD           *754.0 GB   disk2

                                 Logical Volume on disk0s2, disk1s2

                                 5AF6F133-EDD1-4A59-98D9-6398F79F408D

                                 Unencrypted Fusion Drive

/dev/disk3

   #:                       TYPE NAME                    SIZE       IDENTIFIER

   0:     FDisk_partition_scheme                        *15.6 GB    disk3

   1:                 DOS_FAT_32 WININSTALL              15.6 GB    disk3s1

charles-pc:~ Charles$ sudo gpt -vv -r show /dev/disk1

Password:

Sorry, try again.

Password:

Sorry, try again.

Password:

gpt show: /dev/disk1: mediasize=1000204886016; sectorsize=512; blocks=1953525168

gpt show: /dev/disk1: PMBR at sector 0

gpt show: /dev/disk1: Pri GPT at sector 1

gpt show: /dev/disk1: Sec GPT at sector 1953525167

       start        size  index  contents

           0           1         PMBR

           1           1         Pri GPT header

           2          32         Pri GPT table

          34           6        

          40      409600      1  GPT part - C12A7328-F81F-11D2-BA4B-00A0C93EC93B

      409640  1247785824      2  GPT part - 53746F72-6167-11AA-AA11-00306543ECAC

  1248195464     1269760      3  GPT part - 426F6F74-0000-11AA-AA11-00306543ECAC

  1249465224        1144        

  1249466368   704057344      4  GPT part - EBD0A0A2-B9E5-4433-87C0-68B6B72699C7

  1953523712        1423        

  1953525135          32         Sec GPT table

  1953525167           1         Sec GPT header

charles-pc:~ Charles$ sudo fdisk /dev/disk1

Disk: /dev/disk1 geometry: 121601/255/63 [1953525168 sectors]

Signature: 0xAA55

         Starting       Ending

#: id  cyl  hd sec -  cyl  hd sec [     start -       size]

------------------------------------------------------------------------

1: EE 1023 254  63 - 1023 254  63 [         1 - 1953525167] <Unknown ID>

2: 00    0   0   0 -    0   0   0 [         0 -          0] unused     

3: 00    0   0   0 -    0   0   0 [         0 -          0] unused     

4: 00    0   0   0 -    0   0   0 [         0 -          0] unused     

charles-pc:~ Charles$ sudo dd if-/dev/rdisk1s4 count=1 2>/dev/null | hexdump -C

charles-pc:~ Charles$ sudo dd if=/dev/rdisk1s4 count=1 2>/dev/null | hexdump -C

00000000  eb 52 90 4e 54 46 53 20  20 20 20 00 02 08 00 00  |.R.NTFS    .....|

00000010  00 00 00 00 00 f8 00 00  3f 00 ff 00 00 58 79 4a  |........?....XyJ|

00000020  00 00 00 00 80 00 80 00  ff 0f f7 29 00 00 00 00  |...........)....|

00000030  00 00 0c 00 00 00 00 00  02 00 00 00 00 00 00 00  |................|

00000040  f6 00 00 00 01 00 00 00  a5 0a 34 34 11 34 34 82  |..........44.44.|

00000050  00 00 00 00 fa 33 c0 8e  d0 bc 00 7c fb 68 c0 07  |.....3.....|.h..|

00000060  1f 1e 68 66 00 cb 88 16  0e 00 66 81 3e 03 00 4e  |..hf......f.>..N|

00000070  54 46 53 75 15 b4 41 bb  aa 55 cd 13 72 0c 81 fb  |TFSu..A..U..r...|

00000080  55 aa 75 06 f7 c1 01 00  75 03 e9 dd 00 1e 83 ec  |U.u.....u.......|

00000090  18 68 1a 00 b4 48 8a 16  0e 00 8b f4 16 1f cd 13  |.h...H..........|

000000a0  9f 83 c4 18 9e 58 1f 72  e1 3b 06 0b 00 75 db a3  |.....X.r.;...u..|

000000b0  0f 00 c1 2e 0f 00 04 1e  5a 33 db b9 00 20 2b c8  |........Z3... +.|

000000c0  66 ff 06 11 00 03 16 0f  00 8e c2 ff 06 16 00 e8  |f...............|

000000d0  4b 00 2b c8 77 ef b8 00  bb cd 1a 66 23 c0 75 2d  |K.+.w......f#.u-|

000000e0  66 81 fb 54 43 50 41 75  24 81 f9 02 01 72 1e 16  |f..TCPAu$....r..|

000000f0  68 07 bb 16 68 52 11 16  68 09 00 66 53 66 53 66  |h...hR..h..fSfSf|

00000100  55 16 16 16 68 b8 01 66  61 0e 07 cd 1a 33 c0 bf  |U...h..fa....3..|

00000110  0a 13 b9 f6 0c fc f3 aa  e9 fe 01 90 90 66 60 1e  |.............f`.|

00000120  06 66 a1 11 00 66 03 06  1c 00 1e 66 68 00 00 00  |.f...f.....fh...|

00000130  00 66 50 06 53 68 01 00  68 10 00 b4 42 8a 16 0e  |.fP.Sh..h...B...|

00000140  00 16 1f 8b f4 cd 13 66  59 5b 5a 66 59 66 59 1f  |.......fY[ZfYfY.|

00000150  0f 82 16 00 66 ff 06 11  00 03 16 0f 00 8e c2 ff  |....f...........|

00000160  0e 16 00 75 bc 07 1f 66  61 c3 a1 f6 01 e8 09 00  |...u...fa.......|

00000170  a1 fa 01 e8 03 00 f4 eb  fd 8b f0 ac 3c 00 74 09  |............<.t.|

00000180  b4 0e bb 07 00 cd 10 eb  f2 c3 0d 0a 41 20 64 69  |............A di|

00000190  73 6b 20 72 65 61 64 20  65 72 72 6f 72 20 6f 63  |sk read error oc|

000001a0  63 75 72 72 65 64 00 0d  0a 42 4f 4f 54 4d 47 52  |curred...BOOTMGR|

000001b0  20 69 73 20 63 6f 6d 70  72 65 73 73 65 64 00 0d  | is compressed..|

000001c0  0a 50 72 65 73 73 20 43  74 72 6c 2b 41 6c 74 2b  |.Press Ctrl+Alt+|

000001d0  44 65 6c 20 74 6f 20 72  65 73 74 61 72 74 0d 0a  |Del to restart..|

000001e0  00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00  |................|

000001f0  00 00 00 00 00 00 8a 01  a7 01 bf 01 00 00 55 aa  |..............U.|

00000200

charles-pc:~ Charles$

Still it would be great if Apple wrote software that actually worked without you have to follow arcane links that aren't even mentioned during the process after the start screen - especially given how easy it is to end up with an orphaned partition that needs Gparted to recover & a full reinstall. Macs just work...riiiight. next machine is windows, my Mac adventures are done for life.

Hello,

I have just experienced this problem and worked out a fix.  I have a late 2015 27" Retina iMac running el capitan

Looking at the disk it seemed to have a read only attribute and after you format it to NTFS it loses the label.

Therefore try these steps.

Run the BA and start the process

Follow it until you get the error

Then hit escape to exit setup and it takes you back to a screen with Install

At the bottom right is the repair computer part.  Click this,

Go to the advanced options.  I think there are 2 until you see the option for command prompt.

Open the command prompt

Then we will use DISKPART to reformat and label the  partition.

*****  IMPORTANT  PLEASE MAKE SURE YOU SELECT THE CORRECT DISK AND THE CORRECT VOLUME ******

Once in disk part follow these commands

DISKPART> list disk

DISKPART> select disk (the number that matches your bootcamp partition)

DISKPART> attributes disk clear readonly

DISKPART> list volume

DISKPART> select volume (the number that matches your bootcamp volume)

DISKPART> format fs=ntfs label=BOOTCAMP quick

After the format exit diskpart and you should be left at a prompt similar to

X:/sources

just type setup to start setup and carry on as normal.

This time in setup select your partition now named BOOTCAMP but DO NOT FORMAT

Away you go.

Thanks

Madmaxious