Recovery Console W7 bootsect: access is denied


Dear all experts,
as described in
"Option Three: Nuclear Holocaust" from "Recovering the Vista Bootloader from the DVD" in "Dashboard /EasyBCD" help
I tried to run some bootsect command on the drive I want to boot repair but a windows message appearing was: "access is denied"
Some forums give a solution/help to change registry keys about RecoveryConsole to obtain good rights to do valid repair on corrected drive (D: for me)
(del d:\boot\bcd give same result as "access is denied")
The problem: access to other drive than the boot's drive (DVD in that case)
referenced registry key to be modified is
[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Setup\RecoveryConsole]
These keys doesn't exist on W7 when booting from DVD recovery console !
I Just found that "RecoveryConsole ....." fields exist but in:
[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\SeCEdit .... and with different format

Is there a way to correctly access the drive to repair in that case (DVD RC w7) ? Thanks for all help
Are you sure you want D: ?
Being D when it's booted, doesn't mean the booted DVD sees it as the same letter.
It's an OS in its own right and they all keep their own map of letters.
Yes it's D:
when i boot with RC DVD W7 local drive is X:
D: is the drive I want to repair. It's the drive who have /boot/bcd that I need to rebuild
C: drive is a recovery hidden drive from DELL.
best regards