First of all, I am apologize to this thread opener for post my similar problem like him ( cause even I don't know how to open a new thread ), I am a new MacBook user and new in this apple support community.
01. I got a gift (MacBook Pro Retina 2013 earlier model i7 CPU 750GB SSD and 16GB RAM). few days ago. it was not install any OS X, when I power on, it was show recovery screen and Disk utilities and option to install Mountain Lion OS X.
02. Then I search on google and find way to install (Yosemite 10.10) OS X by bootable USB disk. then my uncle have a MacBook pro from his MacBook pro I make a Yosemite 10.10 OS X bootable USB disk for install OS X. According to google search tutorials I did all and finally I installed ( Yosemite 10.10 ) on my MacBook Pro Retina and Update it Yosemite 10.10.3. I was very happy that World best Laptop I have now with high configuration...!
03. But when I know that, Apple give chance to install "Windows" in MacBook Pro then I was also more happy that, I am a Java learner and in windows can test my application and SQL server etc. then I am googling and found about BootCamp. then I followed Bootcamp process from my MacBook Pro Retina and make a windows 8.1 x64 bootable disk and installed windows 8.1 Pro Properly. And installed all the Bootcamp drivers for my Windows that was downloaded from internet Bootcamp software during making Bootcamp windows USB disk.
04. Everything was fine, Suddenly I thought that, if Windows OS is being Virus effected or need to reinstall then my all file will be lost from Windows partition...!
Then I decided that, I should "srink partition" for make a Drive that I can put my Documents, as like as Windows Laptop. My Bootcamp drive was 250GB, I try to Shrink Partition 100GB, " Then it was give me a Warning that, something like Boot Problem or something like that. But I thought it is a Normal Warning...! then I Press Yes. and it was Srink and make a 100GB Partition from Device Manager and I format that Partition. "
05. After that I saw some other Partition also showing now on my Windows My Computer Window. Like C,D,E,F. only C and D drive showing Memory space. Then I afraid and Delete that Partition which I made from Device Manager. and in C drive I Extend Volume, now my Windows Volume showed about 250GB.
06. After This foolish think done, I restarted my Windows and see now Default Boot was OS X. but not boot from that, and come Windows 8.1 Starter Screen and showing error Windows boot Screen and restart again and come windows Logo " Preparing Automatic Repair " and after show " Diagnosing your PC " then "Automatic Repair", " Your PC did not start correctly ". two Option showing " Restart " and " Advanced options". from Advanced option I choice Fix windows starting problem and my Windows come on in normal mode but if I Restart my Windows again it show "Preparing Automatic Repair". but My OS X would not boot any more.
07. After again Googling I saw several solution, But when I turn off my MacBook pro and Press and hold cmd+R it show now " Starting Internet Recovery. This may take a while ".
08. Then I tried to Boot from my USB Bootable Yosemite 10.10 OS X by Pressing Option/alt key, it show " Windows" , " Install OS X Yosemite". then I click on OS X Yosemite and boot it from USB. it show Screen " To set up the installation of OS X, Click Continue " But do not want to Loose my Documents and All my Movie collections in mac OS X partition saved in " My Documents ".
09. Then From OS X Installer Screen it show also "Utilities" option and choose "Disk Utility...". and showing now " 751.28 GB APPLE SSD... > disk0s1, disk0s2, disk0s3 "
When I click on " disk0s1 " it show, > Mount Point : Not mounted. > Partition : Windows_LDM. > Capacity : 521.28 GB ( this is my OS X Partition).
and Under APPLE SSD... there are two disk showing Orange drive " disk2>OS X Install ESD " and " disk3>OS X Base System ".
10. Finally Sorry for long history, Please I need help for my MacBook Pro Retina OS X Boot Partition return and save my all Documents in my OS X Partition and Work fine as work before.
"Advance Honor to the community"