C/E drive confusion

I suspect that your drives were not jumpered properly when the second drive was installed.

Prior to XP, drive letters were assigned in a specific hierarchy.
Primary master is C:
Primary slave is D:
Secondary master is E:
Secondary slave is F:
With the exception, that removable media always is assigned drive letters after ALL fixed media drives.

While the Primary master is the "BOOT" drive, you do not need to have the operating system installed on the C: drive. Just the system files that need to reside in the boot sector of the drive.

With XP, the hierarchy is loosely followed.
That is, drives will be assigned letters per the hierarchy when the XP is installed.
After that, XP assigns the drive letters in sequence as drives are added.

Anyhow, I suspect that the 10GB drive is set as the Primary master drive. That is why it was assigned the letter C: when you re-installed XP.

There is no easy work-around for this.
I would make sure that the drives are jumpered correctly, and re-install XP again.

Chas

Well, the reason can be that the 10GB HDD had the Jumper set as "Cable Select". In this case, when the 60GB was removed, the BIOS recognizes the 10GB as the primary and takes it as a default. The best option would be to ensure that the Jumper on the 60GB is set as a Master and the 10GB as Slave. Also, try to set the BIOS to defaults [Every BIOS has this option named as Load Defaults or Set Defaults].

Once done, restart the computer. This should propably re-assign the drives appropriately.