Just to sum up what occured here and how we were able to get this fixed. Please correct me if I am wrong with anything here augie, so we can be as accurate as possible for future reference. I've included a link to this post/thread
HERE
Windows XP was installed on drive C:\ as a stand alone operating system initially. Windows Vista was then installed to drive F:\, a free standing independant drive on the system, with the Windows XP physical drive unplugged from the system during Vista installation. It was possible to boot into either operating system by changing the boot priority order of the drives in the system BIOS. Each operating system therefore contained it's own boot system files on the root of it's drive.
What we then did was to boot to Windows XP and copy all the Vista boot system files to the root of the Windows XP installation so that all these files appeared on the "System" drive:
Boot (folder) - Critical, must be on the system drive
Boot.BAK
bootmgr - Critical, must be on the system drive
BOOTSECT.BAK
The other critical Vista boot system file is winload.exe and that is always found in the Windows\system32 folder. As the BCD store was already pointing to that correctly, there was no need to move it.
The following Windows XP files also of course are always needed and were already on the system drive:
boot.ini
NTDETECT.COM
ntldr
We then copied bootsect.exe and bcdedit.exe from the Program Files>PROnetworks>VistaBootPRO folder to the Windows\system32 folder of Windows XP so that the necessary commands could be run from Windows XP.
The first command we then ran from the command prompt was:
bootsect /NT60 ALL which has the effect of pulling all valid working operating systems into the Windows Vista bootloader.
The next command we ran was:
bcdedit /set {ntldr} device partition=C: which set the Vista BCD store to look for ntldr on the C: drive. The GUID {ntldr} was used as that is what was shown as being applicable to the Windows XP installation by bcdedit.
We also ran:
bcdedit /set {ntldr} osdevice partition=C: but this was not necessary in this case (haven't figured out why yet but still).
Now we had to again run bootsect /NT60 ALL because we had changed the BCD store and needed to pull the new Windows XP data into the Vista bootloader.
From there on in, the bootloader and BCD store had been brought into sync and the system was able to be booted to each operating system from the Vista boot menu.