Please use this link to the Dell website when installing XP on a XPS 700 with RAID.
http://support.euro.dell.com/support/topics/topic.aspx/emea/shared/support/dsn/en/tree?c=uk&l=en&s=gen&treeid=FFA33DA99941FEDFE030030ABD62041A&journalid=4072C5C514100B35E040A68F272832EE&Query=&SystemID=&ServiceTag=&contenttype=&os=&component=&lang=&doclang=&toggle=&dl=true