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
    2015-10-17T02:28:05+00:00

    Thanks for posting this! Once I changed those values to 0 I was able to change from RAID to AHCI with no issues. On startup windows properly installed the atapi drivers and correctly detected the drives and what was used for a cache disk is now available...... No rebuild needed!

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  2. Anonymous
    2015-08-27T18:10:59+00:00

    Thanks!  This worked for my asus IPIBL-TX (HP d5000t) motherboard.  I was able to get a 4TB drive recognized and formatted using GPT that was only a 1.8 in RAID and IDE mode.  There is another parameter, pciide that could also be set to 0 in addition to the two listed above but the atapi and msahci where the critical ones when the motherboard is in RAID mode.

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  3. Anonymous
    2015-08-09T21:54:34+00:00

    I'd been looking everywhere for a solution. I've got a M4600 Dell and it came with one small SSD in RAID configuration. I upgraded to a new, much larger, Samsung SSD and ran into the RAID vs. ACHI issue. After many hours and re-boots, Dell was no help whatsoever... This fixed it in 30 seconds.... Thanks so much!

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  4. Anonymous
    2015-03-12T07:41:01+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

     

    This solution worked for me while converting a client's broken RAID 1 to AHCI.

    One disk in the array failed, and it was decided to dump RAID and use a better backup solution.

    After switching bios from RAID to AHCI, BSOD's prevented booting into the Win7 OS.

    I switched back to RAID in BIOS, booted into the broken array's OS on the surviving drive,

    applied this fix, rebooted and switched back to AHCI, the disk is now booting fine and running

    Win7  as normal.

    However, The IRST showed an error and couldn't start, so I removed IRST, and the system is running

    as normal now. I will soon attempt to re-install IRST and see if it will run properly, but haven't gotten that far yet.

    BIG THANKS for this solution!

    congo

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