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
    2013-09-21T03:46:42+00:00

    There are dozens of hits in the search engines about this issue (0x7e after switching from RAID to AHCI) and of the ones that are attempting to be helpful that mention the REG key MSAHCI, this was the first one I found that also referenced the ATAPI key as well.

    I have had this issue before and found the answer somewhere but it's been a while and that important part of the solution slipped my mind.

    I had an imaged system restored that BSOD-ed at startup so installed a new copy of Windows 7, started REGEDIT, loaded the SERVICES hive from the original install, and edited the START values to 0. Rebooted the machine and the original OS install now boots.

    I realize this thread is pretty old but if O. Bilal checks his replies to this post, thanks!

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  2. Anonymous
    2014-03-20T12:58:15+00:00

    I just confirmed this fixes my new Latitude E5540.  Bitlocker suspended and unsuspended without trouble either.

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  3. Anonymous
    2014-04-05T16:45:37+00:00

    I had a similar situation with attempting to 'clone' an existing Windows 7 configuration on a Dell Vostro 200 to a new Dell Optiplex 3010. The Vostro 200 only supports ATA mode in native IDE and RAID, and the system would not boot beyond the splash screen (typical when changing ATA mode from IDE to AHCI or vice versa with Windows 7).  This is exactly what I needed to get running properly in AHCI mode on the new machine.

    Thanks a TON!

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  4. Anonymous
    2014-07-08T14:37:24+00:00

    This worked for our firm, on a Latitude E5530.

    Here is a script for all the registry changes that need to be made.

    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

    I think the most important changes were to "msahci" and "atapi".

    Thank you again everyone for the insight, this helped me out!

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