I'm amazed that copying the contents of Windows from one install to another worked at all, but it seems that now you have the 'repaired' XP install thinking it is on drive D?
But reading your post over again, (and again), I am not sure I follow the problem.
In this computer I have, I am using a dual boot system. The one I am using now is Vista, on the C drive, but I have installed Windows 7 RC onto drive F, (D and E are optical media drives). However, when I log into my Windows 7 install, that tells me that it is on drive C. That's perfectly normal.
If, somehow, your XP install that you are talking about appears to recognise itself as on drive D in Windows Explorer, then I do not believe there is an easy way around this. Changing drive labels and names is a sure way to make the OS stop working, and from what I have seen elsewhere, the recommended way to remedy this is to completely re-install.
To get my XP to reboot from my multiple partitioned and multiple drives, I had to copy the windows system directory from a working (C) Windows directory.
The problem now is that Windows sees my original D drive as a C drive while I am in the drive called SATA. Consequently all the mapping is pointing to the C drive. If I am in my real C drive, called Maxtor, it sees it as D in Windows Explorer. If I want to uninstall a program from D SATA drive, it'll install it from my C drive MAXTOR as for the links that do work. Does this make any sense?
Accordingly, I want to remap? C SATA to D SATA like before, but at the same time, I wish to preserve my data on both C SATA and C MAXTOR. I'm not sure if mapping is the correct terminology. I also have WIndows 7 installed too as N drive.
Obviously, reformatting the drive and doing a fresh install of XP would solve this problem but would create more work since I have a total of two XP partitions and one Windows 7 spanned over 3 drives.
Any ideas on how to get my current XP C drive called SATA to be my D drive and my original C Drive, called Maxtor to remain in tact?