I am trying to break my RAID 1 array (using onboard intel raid controller) that has Windows 8.1 installed on it. I then want to switch my bios to AHCI mode and boot from one of those drives. Is it as simple as these 4 steps?

  1. use CTRL-I to enter raid config utility during startup
  2. delete array
  3. switch bios from raid to ahci mode
  4. boot from either drive

I have been reading around and some people say you must take more steps BEFORE deleting the array in order to make the drive bootable afterwards. They suggested uninstalling the RST software or changing registry key "HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\iaStoreV" from 0 to 3, etc.

Its possible those suggestions are outdated though. Anyone mind educating me?

MSI Z87-G41 PC MATE 2 x Western Digital Caviar Blue 500 GB (in RAID 1 with OS) Windows 8.1 Pro 64bit


If you just go through those 4 steps your system won't boot Windows. During Windows installation process, any unused storage drivers are disabled to speed up the OS's startup. When you change the SATA mode you are using you need to change the driver that is enabled as well. For Windows Vista and 7 you had to go and edit the registry but with Windows 8 and 8.1 you can use Safe mode instead as it has all boot-start drivers enabled.

Before performing any changes to the system make sure you have backup of all your important files.

Open an elevated command prompt and set the machine to boot into Safe mode by typing bcdedit /set {current} safeboot minimal Reboot the machine into Safe mode by typing: shutdown /r /t 0

During reboot,  enter raid config utility, delete array, switch BIOS from RAID to AHCI mode, choose SAVE and Reboot. Since the boot device is now used via AHCI, the necessary drivers will also be loaded on subsequent boots.

Reset the bcdedit settings to allow the machine to boot into the Normal mode by typing: bcdedit /deletevalue {current} safeboot

Reboot the machine into Normal mode by typing: shutdown /r /t 0*

  • Great explanation, thank you. Is there any need to then disable those unused raid drivers afterwards? (in order to not slow down the OS startup?) – Mmats Dec 16 '14 at 16:10
  • Windows will load all the drivers only when booting in Safe mode. And you need to do this only once so it can “remember” which is the correct driver to use. On any subsequent boots in normal mod it will load only the drivers it needs. So there is no need to make any other adjustments. – Techpumpkin_WD Dec 17 '14 at 15:26

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.