Windows 8, SSD and AHCI

Discussion in 'Windows, Linux & Others on the Mac' started by MJL, Aug 2, 2013.

  1. MJL macrumors 6502a

    Jun 25, 2011
    Under Windows 7 one could use the instructions as published here:

    Unfortunately that no longer works under 8. Somewhere I found a reference to manually editing the registry in another value: Storahci but that failed too.

    However I did some more digging and found that Microsoft provided the answer:

    The new Winclone 4.2 allows me to back up the AHCI partition (I got an error under Winclone 3 and had to revert it first back to IDE which is a pain in the proverbial place with Windows 8). After restore the patchedcode.bin from the first link has to be applied again and all is fine.

    Hopefully this helps some other soul who has been looking for an answer.
  2. CineBrad macrumors newbie

    Sep 5, 2013
    Still trying to get AHCI on Windows 8

    MJL, This is exactly what I'm trying to do right now - and I'm stuck!

    Mac Pro 4,1 trying to get AHCI working in Windows 8 Boot Camp

    So basically, the Windows article you referenced is saying to go into safe mode on next reboot, and that will allow the AHCI drivers to be added (even though windows thinks they aren't compatible)?

    Could go go into more specific detail what you did to get this working for Windows 8?

    1. set Windows 8 to reboot into safe mode (via elevated cmd prompt)
    2. reboot to OS X disc/recovery partition
    3. using terminal apply the patched code.bin to the mgr
    4. restart to Windows 8, apply correct AHCI drivers (I think Intel ICH 10R in my case)
    5. restart Windows 8 again, install Intel RST

    Is this correct?
  3. MJL, Sep 6, 2013
    Last edited: Sep 28, 2013

    MJL thread starter macrumors 6502a

    Jun 25, 2011
    Did not see your post earlier.

    In Windows 7 what you needed to do was to apply the changes then go into OS X and apply patchedcode.bin.

    I wrote down the following in my Windows 8 install notes for changing it:
    to change to AHCI mode: different from Windows 7
    open command prompt, run as administrator
    bcedit /set {current} safeboot minimal
    shutdown /r /t 0 (that was Microsofts instruction - first time it did not work so did a "shutdown /s /t 0" First is a reboot, second is a shutdown)
    this will load all drivers
    then reboot into OS X and patch the driver with patchedcode.bin (see instructions under OS X)
    edit: reboot in Windows, should now change to AHCI and prompt you to reboot for the new drivers. After successful install remove safeboot
    bcedit /deletevalue {current} safe boot
    shutdown /r /t 0
    end of notes

    I cannot remember the details of doing it. However I have to do this again on another Mac mini that I recently bought and am waiting for parts to arrive (will be shipped from the US) and I expect it will be at least two weeks from now. Then I'll find out how good the above notes are <wink>.

    Hopefully you get it working before then, otherwise you'll have to wait (the other machine is in production now so am not going to experiment on it).


    Just came across a note somewhere on bcedit :
    the whole elevated command line mess with the bcdedit command... You can do the same thing by going windowskey+d (takes you to desktop) and windowskey+r (opens run window) and type msconfig then look under boot > boot options > safe boot > minimal.
    (end quote)
  4. wally21 macrumors member

    Mar 7, 2009
    I'm also in the process of trying to enable AHCI for my Mac Pro running windows 8.

    I have done everything mentioned here and in the OCZ forum, but to no avail.

    Everytime I try to change my StartOverride key to 0 from 3 in the windows registry, it is reset (set back to 3) upon reboot. So, I can't get it to switch over to AHCI mode. I have even tried deleting the key altogether, but it is always there when I reboot. I have done this in safe mode, in normal mode with my antivirus turned off, and nothing I have done yet has worked.

    Any thoughts here?
  5. MJL thread starter macrumors 6502a

    Jun 25, 2011
    read my post above - you are trying to apply a windows 7 solution to windows 8. In 8 you do not need to do any registry modification, you only have to start in safeboot.
  6. Ole1111 macrumors newbie

    Aug 27, 2015
    Is the wake/sleep mode of windows affected after those changes ?
  7. plato1123 macrumors newbie


    Feb 9, 2016
    Is there any way of patching the boot record without OSX? I only have windows 8 installed on my 2010 macbook pro (heresy, I know). THanks!!
    Patrick M

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