I have two drives connected to a Promise 378 raid controller as two independent drives. Xp home is installed on the first drive. My goal is to keep my Xp home drive working while I install XP Pro and all of my apps on the second drive. Then when I have the xp pro drive the way I want it, copy the xp pro partition to the first disk and delete the xp pro partition on disk 2. This is how I tried to do this: I installed Disk Director Suite 10 on disk1 (Xp home). I used DDS 10 to install xp pro on disk 2 and Dual boot between the two operating systems. I understand that windows stores drive letter assignments in the registry under HKEY_LOCAL_MACHINE\SYSTEM\MountedDevices and that this info needs to be reset so that windows will recreate drive letter assignments when the new drive is booted the first time. I did some research on how to do this and found www.goodells.net/multiboot/partsigs.htm. There are 3 methods explained in this article on how to do this with method 3 being the easiest and method 1 as the most difficult. The third method of booting from a W98 boot floppy and running fdisk /mbr won't work because DOS can't see the raid drive. I tried the second method of deleting the registry values on disk 2 before copying the partiton to disk 1. I deleted the xp pro: bootwiz folder and then copied the xp pro partition to disk 1. I disconnected disk 2 and rebooted. The new xp pro partition still won't boot. The only way my system boots now is when I restore the drives to their original configuration using my True Image 9.0 image bkups. So basically, disk2 is slaved to disk 1. Can anyone explain how to successfully do this?