Common problems switching to AHCI under Windows
Enabling AHCI in a system's BIOS will cause a 0x7B Blue Screen of Death STOP error (INACCESSIBLE_BOOT_DEVICE) on installations of Windows XP where AHCI/RAID drivers for that system's chipset are not installed - i.e. boot failure. Switching the chipset to AHCI mode involves changing the BIOS settings. Usually, manual installation of new drivers is required before enabling AHCI in BIOS.[4] Alternatively, a "Repair" installation with the appropriate driver loaded during the setup process usually corrects the problem.
For Intel chipsets (for example, Intel ICH9) drivers are available from either an OEM motherboard or computer manufacturer. For the Intel versions, the driver must be loaded before loading the OS (by pressing F6 as setup starts, then using the floppy disk when prompted).The Intel drivers will work for both XP and Vista. Also, in the case of ICH9, an unsupported method to enable AHCI on ICH9 is available.
When attempting to install Windows XP or a previous version on an AHCI-enabled system, setup will fail with the error message "setup could not detect hard disk drive..." since no drivers will be found for accessing the SATA controller/s. This problem can be corrected by either using a floppy disk or by slipstreaming the appropriate drivers into the Windows XP installation CD, or by turning on IDE emulation in the BIOS settings if it's available (usually labelled COMPATIBILITY or ACPI).
Enabling AHCI in a system with Windows Vista already installed will result in a BSoD if SATA was configured in IDE mode during Vista's installation. Before enabling AHCI in the BIOS, users must first follow the instructions found at Microsoft Knowledge Base article 922976.
Enabling AHCI in a system BIOS on installations of Windows XP or Windows Vista will cause SATA Optical drives to disappear. A Hotfix for Windows Vista is available under the title: "SATA optical drives are not available after you start a Windows Vista-based computer."[5] This problem was fixed in Vista SP1.