Please follow below steps to disable AHCI mode before you install Windows XP. 1. Power on NB and press DEL key when prompted with "Press DEL key to run Setup" message during boot up. This will lead you to BIOS Setup Utility. 2. Move cursor to Advanced tab and change AHCI mode to "Disabled". 3. Press function key "F10' to exit and save changes. NB will reboot again. 4. Now you can install Windows XP.