Formatting an external HD from the Windows XP boot CD

Hi!
My external HD worked fine until I tried CasperXP as a backup solution.
CasperXP ruined the partitioning and formatting of that external HD and
could not even manage to end its own backup for reasons it could not
fathom out by itself. CasperXP could not manage to restore this
external HD to its former state (unknown error!)
CasperXP is now uninstalled from my system. But my external HD is now
in a complete mess and needs reformatting.
To compound matters, Windows XP can only manage to format 94% of it.
Then the formatting goes into some kind of loop and cannot be completed.
I was wondering, would it work better if I tried formatting it from the
Windows XP boot CD (Recovery Console)?
Has anyone any experience of formatting HDs from a Windows XP boot CD?
My main problem is that the external HD is identified by the Recovery
Console as unformatted harddisk0 and drive D: (single partition).
Consequently, my main internal HD is divided into NTFS drives C: E: F:
G: H: I: J: K:
The floppy is drive A:. The CD-ROM drive L:
Can anyone tell me what will happen if I delete partition D:?
Will I be able to recreate it as drive Z: for example?
Will doing so shift the drive letters of the main HD back to drives C:
D: E: F: G: H: I: J: (as it is divided up in "normal" Windows XP)?
I hope my explanations haven't been too confusing!
Thank you very much for any help.
--
Cheers,
Robert

Formatting an external HD from the Windows XP boot CD