The new install of XP on a new drive without the other drive in place would be C and D as you partitoned it. Then when you added the old drive, the new XP should have reidentified your,old partitions.

I did similar but left the other drive in. My XP drive failed, the other drive had four FAT32 partitons.E,F,G.H. I then got the first drive replaced under warranty and reinstalled XP on it. The XP drive was then I and J. Yes, the boot drive was I . system worked fine, however it only had one XP on it.

Can you put a Win 98 boot floppy in and run del directory and delete the Windows directory on the second drive?? Not quite sure of the syntax may be deldir. If the original is in NTFS format then the Win 98 floppy won't work. Just download delpart and run it from a floppy and delete that partiton.

Probably many other ways that will follow.