drive letter config in XP pro

How do I change the drive letter config in XP pro?

I recently installed XP pro on a new HDD, but didn’t connect my other HDD to my comp when it was installing.
Now I have a C: drive(HDD), a D: drive(CDRW), an E: drive(DVD-ROM), and an F: drive(HDD).

I would like to have both of the HDD’s together, ie: a C: drive(HDD) and a D:drive (HDD).
any help would be much appreciated.
Thanks in advance
D