AHCI : Enable in Windows 7 / Vista

Bare Foot Kid said:

bearcave said:

Bare Foot Kid said:

Hello bearcave, welcome to Seven Forums!





If the value in the registry was at ' 0 ' to start with, AHCI was already enabled in Windows.

That's what I had figured,

but why then would it just continually reboot when I set it to AHCI mode in the bios?

Something is out of order, if it's not/wasn't set in the BIOS to AHCI, Windows automatically disables the AHCI drivers during OS install.
Do you have a lot of data to lose if you re-install; just asking.



These are the wrong ones, as far as I know; I haven't used this technology.

Matrix Storage manager" and "Rapid Storage Technologies"

Not data loss, all of my data is on a separate partition and everything "music" "documents" just point to that partition and I have the data backed up. It's more the many hours of reinstalling all of my programs and then tweaking things to the way I like them.

I wonder if I went into the registry, disabled the msachi start=3 rebooted and then went it and re-enabled it would that make any difference? or is there something I can do to the hdd drivers that would change them to AHCI mode?

Bare Foot Kid said:

Can you get to the registry to change the value to find out, at this point, it can't hurt right?

Well i tired it, I went into the registry changed the start value of msachi to 3 rebooted, went back in changed it to 0 shutdown, went into bios enabled achi, and started up. No joy!! I also took off the auto restart and got the standard stop code 0x0000007b.

This is all of the values for msahci in my registry
(default) = value not set
driverpackageid = mshdc.inf_amd64_neutral_a69a58a4286f0b22
errorcontrol = 0x0000003 (3)
group = scsi miniport
imagepath = system32\drivers\msahci.sys
start = 0x000000 (0)
tag = 0x0000040 (64)
type = 0x0000001(1)

There is a sub-folder called Enum
default = value not set
0 = root\legacy_msahci\000
count = 0x0000001 (1)
nextinstance 0x0000001 (1)

I noticed that the driverpackageid says amd64, and i'm running an intel system could this have something to do with it? I have the wrong drivers?

Bare Foot Kid said:

Sorry mate, I'm at the limit of my knowledge here and I have no further suggestions but just for conversation sake, here's a snip of my "Enum" sub-folder, different than yours.

click to enlarge

No worries, I'm at the limit of mine as well. Interesting difference though. is your msachi folder significantly different than mine?

So I ended up breaking down and doing a fresh install with AHCI selected in the bios. I works great. Thanks for all your help.

Funny thing is I did this so I can install Snow Leopard on my other 500gb and dual boot it with windows 7. But I still haven't been able to get snow leopard to install .

Something else to figure out I guess :)

Thanks again for your help.

I have a normal HDD will there be any performance improvements?

bagavan said:

I have a normal HDD will there be any performance improvements?

AHCI is a SATA feature, so when you say a 'normal drive', does it use the SATA (Serial ATA - Wikipedia, the free encyclopedia) or IDE (Parallel ATA - Wikipedia, the free encyclopedia) interface to connect to your motherboard?

If it uses SATA you can use it and may notice an improvement, if it uses IDE then you won't be able to make use of this feature.