OSX Yosemite breaks Bootcamp

Question

I would like to install osx Yosemite on my Macbook retina 15", but some people say it breaks the Bootcamp. Unfortunately i sometimes need to use Windows (8) for work (to use 3D softwares that doesn't accept mac) and my bootcamp. Can i install Yosemite without risking to lose my bootcamp or windows partition?? thanks

Answer 1

Hi Loner,
Unfortunately, should have read this before upgrading the yosemite while having the bootcamp.
I have noticed you have successfully advised some users on recovering the windows files and data.
I have followed your notes:
diskutil list
/dev/disk0
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:      GUID_partition_scheme                        *251.0 GB   disk0
   1:                        EFI EFI                     209.7 MB   disk0s1
   2:          Apple_CoreStorage                         130.7 GB   disk0s2
   3:                 Apple_Boot Recovery HD             650.0 MB   disk0s3
   4:       Microsoft Basic Data                         20.0 GB    disk0s4
/dev/disk1
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:                  Apple_HFS Macintosh HD           *130.3 GB   disk1
                                 Logical Volume on disk0s2
                                 D1498301-E94E-48FF-B819-BF4B24BDAE9C
                                 Unlocked Encrypted
diskutil cs list
sudo fdisk /dev/rdisk0s4
Disk: /dev/disk0 geometry: 30515/255/63 [490234752 sectors]
Signature: 0xAA55
         Starting       Ending
#: id  cyl  hd sec -  cyl  hd sec [     start -       size]
1: EE 1023 254  63 - 1023 254  63 [         1 -     409639] <Unknown ID>
2: AC 1023 254  63 - 1023 254  63 [    409640 -  255259680] <Unknown ID>
3: AB 1023 254  63 - 1023 254  63 [ 255669320 -    1269536] Darwin Boot
*4: 07 1023 254  63 - 1023 254  63 [ 451172352 -   39061504] HPFS/QNX/AUX
sudo gpt -vv -r show /dev/disk0
gpt show: /dev/disk0: mediasize=251000193024; sectorsize=512; blocks=490234752
gpt show: /dev/disk0: Suspicious MBR at sector 0
gpt show: /dev/disk0: Pri GPT at sector 1
gpt show: /dev/disk0: Sec GPT at sector 490234751
      start       size  index  contents
          0          1         MBR
          1          1         Pri GPT header
          2         32         Pri GPT table
         34          6        
         40     409600      1  GPT part - C12A7328-F81F-11D2-BA4B-00A0C93EC93B
     409640  255259680      2  GPT part - 53746F72-6167-11AA-AA11-00306543ECAC
  255669320    1269536      3  GPT part - 426F6F74-0000-11AA-AA11-00306543ECAC
  256938856  194233496        
  451172352   39061504      4  GPT part - EBD0A0A2-B9E5-4433-87C0-68B6B72699C7
  490233856        863        
  490234719         32         Sec GPT table
  490234751          1         Sec GPT header
sudo dd if=/dev/rdisk0s4 count=1 2>/dev/null | hexdump -C
But after this step, instead of obtaining the first row with NFTS files, I got the following:
Manuels-MacBook-Pro:~ manuelgomes$ sudo dd if=/dev/rdisk0s4 count=1 2>/dev/null | hexdump -C
00000000  00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00  |................|
00000200
Does that mean that all is lost??
Could you please elucidate me whether it is possible to recover the data I had in the bootcamp partition and what should be the next steps?
Many thanks,
Manny