If you install OS X on a Windows7/8-installed hard drive, it won’t boot into OS X. You need to overwrite existing GUID created by Windows 7/8 during partitioning.
Here is what you need to do:
- Boot with a a bootable installer for OS X.
- Launch Disk Utility.
- Choose to partition hard drive.
- click on Options… button and select GUID Partition Table to overwrte existing GUID created by Windows 7 / 8.
- Quit Disk Utility and continue your OS X installation.
Notes
You may follow the instruction in Create a bootable installer for OS X Mavericks or Yosemite on Apple to create a bootable installer for OS X.