i have an compaq LAPTOP CQ 40 , preloaded with VISTA. i want to change it to Windows XP Service pack 2. HArddisk is SATA (Fujitsu). while trying to load XP it give a blue screen with msg "BIOS not Compliant...." . from some forum i got knowledge about Sata drivers that can be loaded during setup process (by pressing F6) i have tried it with Microsoft MAtrix manager ... etc. but still the same thing happends. any Solution friends ?