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
    2016-04-19T04:42:54+00:00

    Has anyone done this to a Win 7 machine that has been upgraded to Windows 10?  I realize Win 10 has a separate section on the site, but there's currently nothing there to address this particular reconfiguration.  Thought I'd see if anyone had tried it yet...

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  2. Anonymous
    2016-04-19T05:34:08+00:00

    I did it with an HP that came with W7....actually when using W7 had to change all the settings as HP defaults into their proprietary XRaid thing so I changed all the registry settings to AHCI so I could get SATA III speeds (Samsung SSD kept telling me I was in SATA II).

    By setting it up to boot to ACHI then upgrading to W10 it went without a hitch.

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  3. Anonymous
    2016-04-20T04:42:54+00:00

    Thanks for the response.  This one is already upgraded, so doing it afterwards isn't an option for me.  I guess the real question is if these same registry changes would work for my Win 10 Dell e5460.

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  4. Anonymous
    2016-04-21T03:04:21+00:00

    I would think it all depends on if the Dell defaults to AHCI in the BIOS settings, in other words does it when you do a default boot go to AHCI? My HP had the RaidXpert thing as default so by going to the registry and resetting everything I could find that dealt with AHCI (there were about six or seven) they're listed on this post previously, can't remember exactly how many but doing em all I was in the correct AHCI settings. I know one thing if I updated the AMD SATA drivers it would ALWAYS give me SATA II speeds and I would have to roll em back every time, this on the HP mobo, I have an ASUS now and it defaults to ACHI and all the sata driver updates don't effect the performance like the HP did.

    If the Dell doesn't default to ACHI when resetting the BIOS then by all means do the registry change, boot into ACHI that's what I did and it now stays in AHCI (on the HP) I'm just guessing but I don't see how it wouldn't work in W10 but that is better left to an IT brain. Hey if it doesn't then going back to the settings you had previously shouldn't be too much of a stretch.

    In my deal it was all about taking advantage of SSD speeds, the OEM HP came with an HDD. Funny thing was the specs listed the mobo as SATA III 6gb speeds but until I actually went in the registry settings and changed them manually they wouldn't come any where near close to those numbers and the Samsung SSD migration tool would red flag the results, so by doing all that I was left with generic Microsoft SATA drivers but they worked., then staying away from any sata driver updates.

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