Bootcamp assistant errors, and disk utility can't fix it Boot Camp Assistant says this:


  The startup disk must be formatted as a single Mac OS Extended (Journaled) volume or already partitioned by Boot Camp Assistant for installing Windows.


But when I try to go into disk utility, I have a single partition, Macintosh HD (stock partition), not counting the system 18 MB partition, and it is indeed a "Mac OS Extended (Journaled)" format.

What can I do?  Does that small 18 MB partition actually make that much of a difference? I can't delete it, so it seems to be important.

diskutil list gives:

 rikermacbookpro:~ rikerw$ diskutil list
/dev/disk0 (internal, physical):
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:      GUID_partition_scheme                        *500.3 GB   disk0
   1:                        EFI EFI                     209.7 MB   disk0s1
   2:          Apple_CoreStorage Macintosh HD            398.8 GB   disk0s2
   3:                 Apple_Boot Recovery HD             650.0 MB   disk0s6
   4:                        EFI NO NAME                 104.9 MB   disk0s4
   5:         Microsoft Reserved                         16.8 MB    disk0s5
/dev/disk1 (internal, virtual):
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:                  Apple_HFS Macintosh HD           +398.5 GB   disk1
                                 Logical Volume on disk0s2
                                 A2648FC0-6D9F-4DB8-98FF-22D33E028A4E
                                 Unencrypted
/dev/disk2 (external, physical):
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:      GUID_partition_scheme                        *250.1 GB   disk2
   1:                        EFI EFI                     209.7 MB   disk2s1
   2:                  Apple_HFS Riker Backup            249.7 GB   disk2s2


And sudo gpt -r show disk0:

rikermacbookpro:~ rikerw$ sudo gpt -r show disk0
      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  778989752      2  GPT part - 53746F72-6167-11AA-AA11-00306543ECAC
  779399392    1269536      3  GPT part - 426F6F74-0000-11AA-AA11-00306543ECAC
  780668928     204800      4  GPT part - C12A7328-F81F-11D2-BA4B-00A0C93EC93B
  780873728      32768      5  GPT part - E3C9E316-0B5C-4DB8-817D-F92DF00215AE
  780906496  196198531         
  977105027         32         Sec GPT table
  977105059          1         Sec GPT header
Try to delete volumes disk0s1,s4 ans s5 with: 

diskutil eraseVolume Free Space /dev/disk0s1


and respectively 0s4 and 5 then launch BCA.

Hope this solves the problem.