Well, old Thread..but..
If you have a hidden Partition from VISTA, the OS let you see only the first HD with the first open Partition.
If you boot with emergency tools, or WinPE, the RAM-Area-OS is HD "C" and the normal OS-HD ist "D" or "E".
On my ACER-Computer is the third HD then HD "D", the second HD is "E" and the first HD is "F", boot is "X" and the RAM-OS-Part is "C".
So i must have give alle HD a single Name, like Boot_C, DATA_D and so on.