Unable To Enable AHCI

kawzman

Distinguished
Nov 27, 2013
19
0
18,510
I finally upgraded from HDD to SSD (Samsung 840 Evo, MZ-7TE250) for my OS/programs. I have read that SSDs perform best with AHCI enabled. There are two settings in my BIOS (ver F3B) for my mobo (Gigabyte GA-X48-DS4) dealing with AHCI.

SATA RAID/AHCI Mode. Has three setting options; Disabled, RAID, and AHCI.

Onboard SATA/IDE Ctrl Mode. Has three setting options; IDE, AHCI, and RAID/IDE.

Setting selection seemed obvious; AHCI for both. With those settings my PC restarts in an endless loop after a second or two of loading the Windows splash screen. I have Windows 7 Home Premium 64 bit.

I don’t know how long my mobo has had this issue with enabling AHCI since my previous setup was running two Seagate Barracuda 500GB HDDs in RAID 0. This has been my setup since I built it in 2008, so I have never needed to enable AHCI. I decided to upgrade to SSD once one of the HDDs in RAID was starting to fail; has now failed.

To keep my PC running until I could perform a fresh install of the OS and programs onto the SSD in a couple weeks, I used the Samsung Data Migration utility that came on a CD with the SSD to image the OS/program partition from my RAID HDDs to the SSD. I haven’t had any issues running the OS or programs.

****************************

Troubleshooting tried so far.

1. SSD working with SATA RAID/AHCI Mode set to RAID and Onboard SATA/IDE Ctrl Mode set to AHCI.

2. Verified all drivers and firmware are up-to-date.

3. Tried every configuration possible for the two settings discussed above to see what would work. Was able to boot into OS with every combination except where SATA RAID/AHCI Mode was set to AHCI.

4. With both modes set to AHCI, as a long shot, tried using Win 7 disk to boot into OS. Also tried Win 7 repair from the disk. Both failed.

5. Googled and googled for this issue and this mobo with no solid leads to a solution.

****************************

Any suggestions and comments would be appreciated. Thanks as always.

Cheers,

Aaron
 
Solution
You need to set AHCI in BIOS before you install windows. There is a work around though.

In the registry, navigate to: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\msahci

Then right-click on the word Start on the right-side and click Modify. Change the value to “0” and click OK. Exit Regedit, reboot the system into BIOS, and change your sata controller to AHCI, save & exit then boot into Windows.

EDIT:
You probably need to boot into BIOS and set it back the way it was when you were able to boot. Then follow the instructions.

When you upgraded the ssd did you reinstall windows? Or did you use copy the install from the hdd to the ssd? It makes a difference as the boot drivers for ACHI are not present. I believe you can inject them but I don't know how. It's always better to just set the bios to ahci then reinstall windows on the new ssd.
 
You need to set AHCI in BIOS before you install windows. There is a work around though.

In the registry, navigate to: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\msahci

Then right-click on the word Start on the right-side and click Modify. Change the value to “0” and click OK. Exit Regedit, reboot the system into BIOS, and change your sata controller to AHCI, save & exit then boot into Windows.

EDIT:
You probably need to boot into BIOS and set it back the way it was when you were able to boot. Then follow the instructions.

 
Solution