After installing Windows 8.1 on a Mac using BootCamp, an 8GB partition called OSXRESERVED is left behind. How would one safely remove it and reclaim the space for the OS X partition without reinstalling OS X or Windows?
Helpful Background Info:
- The hardware is a 13 inch MacBook Programming, retina, early 2015, 256GB SSD, running OS X El Capitan (10.11.2).
- There were no other partitions to begin with. Just Macintosh HD, the Recovery HD, and the EFI partition.
- Using the BootCamp utility, the hard drive was partitioned with 64GB for Windows and the rest for OS X. An iso of Windows 8.1 was on a USB drive and selected with the BootCamp utility for the install. All instructions were followed, and the Apple drivers were installed (and I checked for updates), all without any issues.
- After completing the installation, I upgraded to Windows 10 using the downloader on the Microsoft site before booting into OS X again.
I have already removed the OSXRESERVED partition using the BootCamp utility, which also removed the Windows partition. Everything Windows therefore had to be reinstalled, which is very annoying, hence this question. This is the second time it has happened too, but it does not happen every time I set up BootCamp. Presumably the BootCamp utility is supposed to delete it when its done.
Searching around the web, I've noticed that CoreStorage causes a lot of issues for SSD's and Fusion drives with BootCamp. However the reserved partition has been deleted successfully after, just now, reinstalling Windows using Boot Camp again. CoreStorage was enabled on Machintosh HD. All is good.
Disk Utility did not Work:
Last time it happened, I used disk utility to simply delete the partition. Afterwards, it would not let me expand the OS X drive to occupy the free space and made the Windows partition un-bootable (blue screen + sad face). I think the OS X Disk Utility configures the MBR incorrectly in these circumstances, amongst other things. In addition, the BootCamp utility tried to tell me I had too many partitions to remove Windows. Que full system reinstall! I will not do that again.