http://msdn.microsoft.com/en-us/library/windows/hardware/gg463059.aspx

Microsoft has completely reengineered the boot environment for Microsoft Windows Vista to address the increasing complexity and diversity of modern hardware and firmware.

http://www.pronetworks.org/forums/how-to-edit-the-windows-vista-boot-menu-options-t79102.html

  bcdedit /set {5189b25c-5558-4bf2-bca4-289b11bd29e2} description "Windows Vista Build 5270 x64"

Changes the text of the boot menu line for any other Vista installation. One must use the GUID for that particular installation as shown when one runs the bcdedit or bcdedit /enum all command

Correcting changes to the Partition/Disk structure

Where a partition or a hard drive has been added or removed and has caused the partition/disk structure to change, this can be corrected by running these commands in the order shown:

  X:\>X:\boot\fixntfs.exe -lh -all (Where X: is the drive/partition on which the folder "boot" is to be found)

  bcdedit /set {5189b25c-5558-4bf2-bca4-289b11bd29e2} device partition=X:

Changes boot partition of the OS whose GUID is indicated. (Where X: is new drive/partition required). Must be used together with the osdevice command below

  bcdedit /set {5189b25c-5558-4bf2-bca4-289b11bd29e2} osdevice partition=X:

Changes boot partition of the OS whose GUID is indicated. (Where X: is new drive/partition required). Must be used together with the device command above