Changing from RAID to AHCI

Anonymous
2010-10-28T12:24:52+00:00

Hi,

on my Dell E6510 I have my disk drive set to RAID mode. I have issues using the eSata port so I want to switch to AHCI. I followed the instructions here:http://support.microsoft.com/kb/922976. However when I boot my system after setting the disk mode to AHCI in the BIOS I see the Windows logo (using Win7 x64) and some seconds later I get a bluescreen with a message I can't read because the system is rebooting. Changing the BIOS back to RAID brings up the system again...

Anything I can do to make AHCI working?

Thanks,

Thomas Pagel

Windows for home | Previous Windows versions | Devices and drivers

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Anonymous
2010-11-03T18:05:23+00:00

Hi Thomas,

Thank you for your post.

I believe I have the solution to your problem and I verified it against a Dell machine that has similar controller with your machine. Changing from AHCI to RAID,http://support.microsoft.com/kb/922976 fix will work.  

Changing from RAID to AHCI, you need one more step. Msahci driver requires Atapi.sys miniport to be loaded during boot as well. So you need to change theStart value to 0 for both of the following entries in your registry. You can use regedit.exe utility. 

HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\msahci

HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\atapi

Or you can also simply run the below command lines in an elevated window.

REG ADD HKLM\System\CurrentControlSet\Services\msahci /v Start /d 0 /f /t REG_DWORDREG ADD HKLM\System\CurrentControlSet\Services\atapi /v Start /d 0 /f /t REG_DWORD

Regards

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  1. Anonymous
    2014-09-22T20:48:53+00:00

    HP AMD owners!!!   I'll be a S.O.B....after dealing with this issue for months and months found this post from Toms Hardware and it works!!! I was able to clone/migrate my HP Win7x64 Hm Prem OS to a Samslung    (that's right it almost got slung) 840 SSD did all the listed registry changes (from 3 to 0 in Start) reboot go to F10 change the Storage from RAID to AHCI and bingo it booted up and when it did Windows downloaded all the necessary drivers and did another restart, man no more doing clean installs in AHCI mode!!!!

    One caveat I found iaStorV (rather than iaStor) changed it to 0 in the Start path... was kinda crossing my fingers on that one..but sports fans it works!

    Thank you all I owe somebody a beer.

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  2. Anonymous
    2014-10-30T17:22:28+00:00

    Very Thanks, 

    HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\msahci

    HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\atapi

    my windows run perfectly from raid to ahci. THANKS !!!! :)

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  3. Anonymous
    2014-12-02T12:38:17+00:00

    Thank you for posting this!  4 years later and your post is still helping IT peeps save time and money.  I needed to switch from RAID to AHCI on an Optiplex 990 to get maximum performance out of an SSD and this was right on the money!

    BK

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  4. Anonymous
    2014-12-03T16:17:34+00:00

    I did this and rolled back my AMD SATA driver to Windows ATA and bingo I went from SATA II speeds on my Samsung SSD to SATA III. Samsung Magician was giving me fits trying to 'Optimize'. Why I wasn't seeing SATA III, even HP's gurus didn't know (or they wouldn't let on), they told me I would have to get another MotherBoard, which they of course said would void my warranty., The MB was configured for RAIDXpert which uses an AMD SATA driver that only reaches SATA II speeds; going into Device Manager and rolling back the IDE/ATA Controllers (after following all the registry settings and BIOS changes) then rebooting, I now have the correct speeds. Windows Update will try to give you (if you have AMD Controllers) a newer AMD SATA driver.  I did try it, thinking it would be okay, but what it did was return my controllers to the lower speeds, so FYI do not apply this update and just stay with the stock controller. This information only pertains to HP models with stock (OEM) AMD RAIDXpert configurations, also note I had to change more than two registry files, there is an earlier post that lists:

    REG ADD HKLM\System\CurrentControlSet\Services\msahci /v Start /d 0 /f /t REG_DWORD

    REG ADD HKLM\System\CurrentControlSet\Services\atapi /v Start /d 0 /f /t REG_DWORD

    REG ADD HKLM\System\CurrentControlSet\Services\amdsata /v Start /d 0 /f /t REG_DWORD

    REG ADD HKLM\System\CurrentControlSet\Services\nvstor /v Start /d 0 /f /t REG_DWORD

    REG ADD HKLM\System\CurrentControlSet\Services\nvraid /v Start /d 0 /f /t REG_DWORD

    REG ADD HKLM\System\CurrentControlSet\Services\iaStor /v Start /d 0 /f /t REG_DWORD

    Change the above settings then boot to BIOS  then change the RAIDXpert to AHCI  reboot  then goto Device Manager drill down to the controllers for your original setup and roll it back in Properties and go with the Standard ACHI 1.0 Serial ATA Controller which in my case allowed SATA III.

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