Can the identifier of a partition be changed without modifying the partition? Currently when I try to use BootCamp Assistant on 10.11.5 it gives me the error "The startup disk cannot be partitioned or restored to a single partition." My drive only contains the necessary partitions for OS X to run.

Running diskutil list in Terminal outputs:

/dev/disk0 (internal, physical):
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:      GUID_partition_scheme                        *3.0 TB     disk0
   1:                        EFI EFI                     209.7 MB   disk0s1
   2:                  Apple_HFS Macintosh HD            3.0 TB     disk0s2
   3:                 Apple_Boot Recovery HD             650.0 MB   disk0s4
/dev/disk1 (external, physical):
   ...


I suspect that the issue may be caused by the fact that Recovery HD is not disk0s3, causing BootCamp to think that there are extra partitions on the disk.

Is there a way to change the identifier of the partition without affecting its contents? (Or if this is not what is preventing BootCamp from working, what is?)

Edit:

Running sudo gpt -r show /dev/disk0 outputs:

       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  5858853952      2  GPT part - 48465300-0000-11AA-AA11-00306543ECAC
  5859263592     1269536      3  GPT part - 426F6F74-0000-11AA-AA11-00306543ECAC
  5860533128           7         
  5860533135          32         Sec GPT table
  5860533167           1         Sec GPT header


Running sudo fdisk /dev/disk0 outputs:

Disk: /dev/disk0    geometry: 97451/255/63 [1565565872 sectors]
Signature: 0xAA55
         Starting       Ending
 #: id  cyl  hd sec -  cyl  hd sec [     start -       size]
------------------------------------------------------------------------
 1: EE 1023 254  63 - 1023 254  63 [         1 - 4294967294] &lt;Unknown ID&gt;
 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      


I am using a late 2012 iMac.
The specific problem detailed in this question was solved automatically upon restart (not the first restart however).

Unfortunately, this was not the cause of the BootCamp issues (or any other issues), which were due to the size of my hard drive being greater than 2.2TB. This caused BootCamp Assistant to fail to partition the hard drive because it did not believe that it would work with a hard drive of this size, although the bug in question had already been patched.

To resolve this, the partition was created in Disk Utility. Contrary to what most sites dictate, the Windows partition was not in the first 2.2TB of the hard drive and was not formatted as FAT. This is because it was deleted and recreated as a valid format upon installing Windows. Note that this did not work first time in this case, with Windows giving an error. If this occurs, just delete the partition again (still from the Windows installer) and create a new one. Before doing any of this, all data should be backed up, as if one of the steps fails, it may wipe your data.

The install disk was created with BootCamp like usual.

Edit:

Running diskutil list outputs:

/dev/disk0 (internal, physical):

   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:      GUID_partition_scheme                        *3.0 TB     disk0
   1:                        EFI EFI                     209.7 MB   disk0s1
   2:                  Apple_HFS Macintosh HD            2.5 TB     disk0s2
   3:                 Apple_Boot Recovery HD             650.0 MB   disk0s3
   4:         Microsoft Reserved                         16.8 MB    disk0s4
   5:       Microsoft Basic Data BOOTCAMP                500.2 GB   disk0s5
/dev/disk1 (external, physical):
   ...


Running sudo gpt -r show /dev/disk0 outputs:

       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  4881805104      2  GPT part - 48465300-0000-11AA-AA11-00306543ECAC
  4882214744     1269536      3  GPT part - 426F6F74-0000-11AA-AA11-00306543ECAC
  4883484280         392         
  4883484672       32768      4  GPT part - E3C9E316-0B5C-4DB8-817D-F92DF00215AE
  4883517440   977014784      5  GPT part - EBD0A0A2-B9E5-4433-87C0-68B6B72699C7
  5860532224         911         
  5860533135          32         Sec GPT table
  5860533167           1         Sec GPT header


Running sudo fdisk /dev/disk0 outputs:

Disk: /dev/disk0    geometry: 97451/255/63 [1565565872 sectors]
Signature: 0xAA55
         Starting       Ending
 #: id  cyl  hd sec -  cyl  hd sec [     start -       size]
------------------------------------------------------------------------
 1: EE 1023 254  63 - 1023 254  63 [         1 - 4294967294] &lt;Unknown ID&gt;
 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