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
    2010-10-29T19:36:10+00:00

    Hi Thomas,

    Richard has the right idea about your problem. Windows may be using different storage drivers for RAID and AHCI modes. Windows will try to load the RAID driver but the driver will not match the AHCI mode and bugcheck with famous 0x7B (INACCESSIBLE_BOOT_DEVICE). Startup repair will not work because it will not know which driver to load.

    The easiest way is to reinstall the OS with AHCI mode.

    Going back to the core problem, what issues are you seeing using the eSata port in RAID mode? 

    PS:When changing SATA Mode, BIOS should warn you, saying something like "Attention! SATA mode changing may prevent the present operating system from booting or require a reinstall".

    Thanks

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  2. Anonymous
    2010-10-28T20:13:59+00:00

    Probably the only way to fix it would be to reinstall Windows in AHCI mode. The boot drive no longer has the proper drivers when you change the drive mode in BIOS after Windows is installed.  You could try a startup repair as well but I don't know that it would succeed since it may not even see the drive(s) at startup.

    "Thomas Pagel" wrote in message news:*** Email address is removed for privacy ***...

    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

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  3. Anonymous
    2010-10-28T18:48:23+00:00

    I added the second drive later, it's completely different and even removable... So it's not JBOD...

    The funny thing is that the systems starts to boot... I see the Windows start screen, it's loading some drivers and then it stops... As I said in my initial post I just can't read the message of the blue screen... It's at that moment when you usually wait a second and then see the mouse pointer...

    Thomas Pagel

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  4. Anonymous
    2010-10-28T18:44:00+00:00

    Usually if raid config is selected, and depending on the raid controler, the drives may have to be set as JBOD under that controler.

    I havent looked at the specs of your Dell, are you able to easily remove one of the drives, without opening the case? and if so, if you then set the BIOS to ahci, and disable raid, does the system boot?

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