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
    2011-08-19T00:46:45+00:00

    I know your post is a bit old, but just wanted to let you know that your procedure just worked perfectly for me on a new Dell Latitude E6520, and though it might be my imagination it really seems to me like the computer responds better off the hard drive in AHCI mode instead of RAID mode.

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  2. Anonymous
    2010-11-03T20:05:42+00:00

    Hi,

    you're the man!!! It works!

    I guess it would be a great idea to update the KB article now ;-)

    THANKS!!!

    Thomas Pagel

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  3. Anonymous
    2010-11-01T15:03:23+00:00

    Where did you read they should not both be enabled?

    The article suggests they are turned off just for boot up speed, which indicates they can both get loaded. For example during windows setup, many, many drivers are loaded, just to make sure that accessing the appropriate drivers is possible.

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  4. Anonymous
    2010-11-01T10:29:13+00:00

    I can remove the second drive, no problem.

    Yes, it's only one controller, I see both drives listed there...

    Thanks,

    Thomas Pagel

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