Save the BIOS changes and then press Enter to reboot.
When XP reboots, you should see another 'System Settings have changed' prompt - restart the system again (may require several reboots).
18. Now check that the correct AHCI chipset driver has been successfully installed (for an example, see image below).
Troubleshooting
Blue Screen of Death
If you have a BSOD (e.g. 0x0000007B error) after changing the BIOS to AHCI mode in Step 17, simply change the BIOS settings back to IDE mode and try again.
With any luck it should boot back to XP again - if it does not then you may have trashed the OS by installing the wrong driver - try using the F8 key to boot in Safe Mode (in IDE BIOS mode).
If that does not work, try the BIOS is AHCI mode + Safe Mode. If that doesn't work, you will need to re-install XP!
Identifying the correct AHCI driver
You need to determine what chipset you have and then find the correct driver for the SATA AHCI interface.
One way to find the PCI ID of the SATA controller is as follows:
1. Make a bootable USB Flash drive using RMPrepUSB - choose the FreeDOS option and allow RMPrepUSB to set the Copy OS folder to .\FREEDOS_USB_BOOT, use FAT32 and BOOT AS HDD options and then click on 6 Prepare Drive to format the USB drive as a bootable FreeDOS USB pen.
2. Check using the RMPrepUSB F11 key that the USB drive will boot and select the 2 Boot FreeDos as Hard Disk option, check that it boots to the FreeDOS command prompt inside the QEMU emulator.
3. Insert the USB Flash drive into a USB 2.0 port of your target system
4. Reboot you XP Windows target system and change the BIOS options to Hard Disk = AHCI mode
5. Change the boot options so that the target system will boot from the USB drive first and as a hard disk and Save and Exit from the BIOS setup menu
6. The target system should now reboot from the USB Flash drive to the grub4dos menu - choose menu item 2 Boot as FreeDOs Hard Disk
7. Type