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I had Windows 7 installed via Bootcamp but I messed things up when I tried to install Ubuntu as a third OS. Now my goal is to go back to OS X and Windows 7/8.1 dual boot. However, when I go to Boot Camp Assistant I get the following message when I select the disk where I need to install Windows.

This disk is your os x startup disk and appears to have been partitioned by another utility.

How can I re-install Windows 7 via Boot Camp Assistant?

The following may be useful:

sudo gpt -r -vv show disk0

gpt show: disk0: mediasize=120034123776; sectorsize=512; blocks=234441648
gpt show: disk0: PMBR at sector 0
gpt show: disk0: Pri GPT at sector 1
gpt show: disk0: Sec GPT at sector 234441647
      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  162535816      2  GPT part - 48465300-0000-11AA-AA11-00306543ECAC
  162945456    1269536      3  GPT part - 426F6F74-0000-11AA-AA11-00306543ECAC
  164214992       1840         
  164216832    3817472      4  GPT part - 0657FD6D-A4AB-43C4-84E5-0933C84B4F4F
  168034304   66407311         
  234441615         32         Sec GPT table
  234441647          1         Sec GPT header

sudo fdisk /dev/disk0

Disk: /dev/disk0    geometry: 14593/255/63 [234441648 sectors]
Signature: 0xAA55
         Starting       Ending
 #: id  cyl  hd sec -  cyl  hd sec [     start -       size]
------------------------------------------------------------------------
 1: EE 1023 254  63 - 1023 254  63 [         1 -  234441647] <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

I have a mid 2010 13" MacBookPro running 10.9.2

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1 Answer 1

Yah disk utility is bound and determined to not let you (or itself) potentially erase any more data, especially if it sees the signature of another disk partitioning utility. Welcome to the Wonderful World of Macintosh Computing... sigh.

Probably your best bet is to back up your Mac and Windows data (if not already) and boot the Mac from the COMMAND-R keyboard shortcut and wipe and reinstall from scratch. Your Ubuntu installer has gone and done some things to the partition table that Apple doesn't like and it is likely not going to be recoverable easily.

You could likely haunt the Ubuntu forums as I am sure this has been done and CAN be done. Heck there might even be someone around these parts with that experience. But if you need the Mac back up and running ASAP the quickest way might just be to repartition and start from scratch.

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