Moving XP to another Harddrive, Dual boot with Vista

First, let me apologise if this has been asked and I haven;t found the appropriate answer, I;ll try not to be long winded.

This is the first time I have built a system from the ground up.

I originally planned a dual boot set-up with Vista and XP on separate Hard Drives using 2 Raptor 150 gig drives, and having 2 500gb drives for data storage. Unfotunately one of the 150 gig drives was defective. In the mean time, I temporarily installed XP on one of the 500 gig drives first, then installed Vista on its permanent 150 gig drive. The dual boot has worked flawlessly to this point.

Now my second 150 gig is back from warranty but I cannot get XP off the 500gig drive. I have followed the instructions on the "Remove XP from an XP/Vista Dual boot" with no success, cannot reformat the drive.

To make matters worse, my drive paths are as follows in my comp settings, C:/ 150 gig Vista drive, D:/ 500gig XP drive, e:/data drive. When booting using either XP or Vista Install disks it finds the OS on e:/. I didn;t want to proceed with a repair/forced reformat without knowing what this will do. As it stands now, the computer is working fine, I just don;t want to leave XP on that 500gig drive.

Any help would be greatly appreciated.