I recently installed Windows 8.1 on my MBP (running Mavericks) using Boot Camp.
Everything worked great, but I quickly realized I hadn’t made the partition big enough. So I made a backup of my BOOTCAMP drive, used Winclone 4 to create an image of the drive to restore from, and used Disk Utility to erase the BOOTCAMP partition.
When I tried to create a new partition using Disk Utility, it wouldn’t do it; I could add a partition in the “Volume Scheme” box, I could give it a name, choose a format and size, but the “Apply” button was greyed out.
So I closed Disk Utility, opened Boot Camp Assistant, and started the Windows installation again, but stopped the process after Boot Camp Assistant (successfully) partitioned the disk. I reopened Winclone and restored Windows from the image I created earlier.
Before, my alt/option startup choices were:
[my OS X drive] [Recovery 10.9] [BOOTCAMP]
but now they are:
[my OS X drive] [Recovery 10.9] [EFI Boot],
[EFI Boot] boots into Windows and everything works fine, just as it had before.
Anyways, my question is: what happened to [BOOTCAMP] (it still shows up in Disk Utility and seems fine), what is [EFI Boot], and is this a problem I need to fix or do I not need to worry about it since everything is working fine?