This may not help but sometimes other experience helps piece the puzzle together. I am not sure if there are changes in Win 8 BCD but it seams to be understood that Vista and Win 7 are fairly identical so I am not sure if everything translates through to Win 8. I did notice however, on trying to set up my XP sp3 with Vista and after moving the XP partition and causing it to non boot, that there were things that did not seam to be right.
I have read two different things being 1). These three files have to be in the 'System' partition. I understand this to be where BCD files are and in my case would be Vista on C: 2.) That these 3 files should be in both roots (in my case Vista C:, and XP X
My Experiance:
My XP root had ntldr and NTDETECT files but no BOOT.ini file.
My Vista root had NONE of these three files.
For the sake of eliminating argument: Both systems are set to 'show hidden files'
I created a new BOOT.ini and tried adding it to the Vista root even though it did not show it and it told me it already existed and asked if I wanted to replace it.
When trying to add the new BOOT.ini file to the XP root, upon clicking the save button it will not save and does nothing.
And so it goes, I am still trying to fix my problem and if anyone has an answer click my name and write me a response It is the only post I initiated.