reverse OS and System drive letters without reinstall?

Oops..... chopped off portion of my post AND said "reboot" when I
meant "reinstall" on the topic line. Here is the corrected topic with
the last few lines that were missing from post of few moments ago:

----->>>>

Hi,

Currently have a multi-boot system, with (among other OS's) 3 WinXp
partitions (one on each Hard Drive), set up as follows:

Disk 0 Disk 1 Disk 2

(C) WinXp-A (2300MB) (*)WinXp-B (*)WinXp-C
(J) WinXp system (50MB)

Each WinXp partition is designated as "C" and am using Powerquest's
BootMagic 7.0 to select one at boot-up, with the other two remaining
hidden. The "J" system partition contains only a few files (boot.ini,
ntloader, NTdetect, as well as the reovery console files).
Actually...bootmagic is loading the system partition first, and then I
have to select which Windows partition to use from the multi-boot
screen.

My question is this.... I would like to reverse (or change) the
letters. Make the system partition the "C" partition and the Windows
partitions some other letter. I have successfully changed assigned
letters for the system partition (Using Partition Magic) and for many
other situations without a hitch, but cannot seem to find a way to
change my configuration as described. Would like to change to THIS:

Disk 0 Disk 1 Disk 2

(J) WinXp-A (2300MB) (*)WinXp-B (*)WinXp-C
(C) WinXp system (50MB)

Is there a way to do this WITHOUT RE-INSTALL? I had given up, but when
I installed XP on my daughter's PC a couple of days ago
(yes...separate legitimately purchased WinXp), I was able to set up
exactly as I showed above. But of course that WAS a fresh install.
So...because of that, I started trying again to modify the setup on my
PC, but it won't boot after I make the change.

I;m actually running XP Pro, and she has XP Home, but I doubt that's a
factor.

Any input/suggestions appreciated.

Thanks,
Larry