Need help: Change bios setting from RAID to AHCI?

I am in the process of making some software modifications that will not work with a RAID bios setting. I am trying to set it to AHCI, but windows 7 becomes inaccessible and bsods on boot. Is there a registry value I can change from RAID to AHCI in windows to fix this?

 

Hey there Technos,

If I remember correctly in order to change from a dual hard drive setup running in a RAID array configuration you will need to reinstall the OS. Start fresh or so to speak.
So unfortunately you will have to backup everything and then reformat.

Are you running 2X hdds in RAID 0 or 1?
I'm not to familiar with the R3 configuration. Somebody correct me if I am wrong.

If you are running 2X hard drives in a RAID array setup; either RAID 0 or 1 then it will BSOD when you try to start the OS when running on AHCI setting in the system bios.
In most cases when an OS is installed on a RAID array setup you will have to reformat the drives if you no longer want to utilise the RAID array hard drive setup. That is why your system BSODs every time it is trying to load Windows.

Cheers.

 

I have no idea why Alienware makes the default drive setting "RAID" especially when your laptop only has one HDD, it makes things so much more complicated.

 

Ah if it only has one hard drive in the R3 then I too am confused as too why the setting is set to RAID.

Cheers.

 

Well first off from what I read and my benchmarks, when raid mode is set it will run the drives in the best mode possible, even for single drives. That is the reason that AW come with default setting of RAID even on a single drive configuration.
So setting to ahci does not benefit and my tests back that up. However if you need to go to ahci here is how to do it.

http://support.microsoft.com/kb/922976

After this go and check the following key as well. Atapi.sys needs to be enabled as well. To do this you have to change the start value of the following entries to 0.

HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\msahci
HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\atapi

 

I am curious about this. How does RAID benifit a single drive over ACHI? If I am running a single SSD for apps and a single HDD for data, wouldn't I want ACHI, not RAID?

Currently I am running a single HDD in RAID (which is the AW default that it came with). But to update my SSDs firmware I have to be in ACHI, so basically I have to reinstall everything just to update my SSD, what a pain.

 

I have two drives, but windows is configured to use only one drive (the other has MAC OS X on it), which is why I am confused as to why RAID was set when there is only one hard drive. Since there is only hard drive, changing from RAID to AHCI shouldn't be an issue. I know it can be done in the registry, I just forgot how.