Windows 7 - Installing Windows XP 32 on a PC running Windows 7 64

Hi. I have a computer up and running with six drives and Windows 7 64 bit. I need to do the following:

1) Delete Windows 7 from my current C drive (It's an SSD and it's running out of space, so I've bought a new one)
2) Install Windows 7 on the new and larger SSD and make it my new C drive.
3) Install Windows XP on the smaller older SSD which will be downgraded to a 3 G/s controller.

I don't want a dual boot setup, but to be able to select booting from the XP drive in the BIOS those very few times I will need to run Windows XP (I need it for some old Nikon film scanners that wont run under Windows 7).

How do I go about this eithout ruining anything? Much appreciate all the help I can get.

Wise to dual boot only via the BIOS to keep the HD's indepedent.

Toward that end unplug all other drives as you install each OS to it's drive.

You will likely need SATA controller drivers for XP installer if it doesn't see the SSD or Bluescreens. Use a SP3 installer to give yourself an edge: SATA Drivers - Load in Windows XP Setup on Dual Boot
SATA Drivers - Slipstream into Windows XP CD