Yosemite + Windows 8.1 Boot Camp BCD error

theriddler said:

I did everything in Boot Camp Assistant, when my MBA is rebooted to the Windows installer, I get a BSOD:

The Boot Configuration Data for your PC is missing or contains errors.

File: \EFI\Microsoft\Boot\BCD
Error code: 0x000000f

Rebooted, and tried to boot directly from WINSTALL instead of EFI Boot (where it gives the BCD error), I get this error:



Repeated formatting from Disk Utility and the Windows installer doesn't work.

Click to expand...

When Disk Utility formats a partition as FAT32, it actually does it in a hybrid MBR way. This means that OS X will see it as GPT and Windows will see it as MBR.

In order for Windows to see it as MBR, download gdisk and run it from Terminal to remove the hybrid MBR.

In Terminal, type sudo gdisk /dev/disk0 (or whatever your internal drive is. You can find out by typing diskutil list and locating the disk#)

Type p to view the partition table to make sure you're working on the right disk.

Type x to enter expert menu.

Type n to create a fresh protective MBR. This'll remove the hybrid MBR so that both OS X and Windows will see the entire drive as GPT.

Type w to save your changes and confirm the change.

This should work. After that, startup from EFI boot and try installing again.

Note: So far, only Haswell MacBook Airs will play nicely with a UEFI installation of Windows. I'm not sure whether Ivy Bridge and earlier MacBook Airs can do it or not.