Changing from RAID to AHCI

Anonymous

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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Anonymous

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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54 additional answers

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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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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Anonymous

2015-12-22T23:24:06+00:00

Fantastic love this.. worked perfect on a dell e6420 ..saved me a lot of head aches :)
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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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