[Blind-sysadmins] Vista ultimate/business downgrade rights/Generic SATA driver

Hello list, Has anyone ever used the vista downgrade rights before? How does that work? Also, I have a Toshiba laptop with vista business and I want to downgrade it to XP pro. Toshiba does not provide an XP sata installation driver. Is there a generic sata driver I can use so that the XP install will recognize the sata controller/hard drive? Thanks again, /David?