AHCI : Enable in Windows 7 / Vista

AHCI : Enable in Vista and Windows 7 after OS install​

   Information

AHCI Advanced Host Controller Interface makes NCQ Native Command Queing along with hot-plugging or hot swapping through SATA Serial-ATA host controllers possible; Vista was the first to offer this feature. The issue with AHCI is it needs to be enabled in the BIOS prior to OS installation; doing so after you have installed the OS will disable the PC. The reason why is Windows disables the AHCI drivers not needed durring installation.

This tutorial will show you how to enable AHCI after you have installed the OS if you didn't already have AHCI enable in the BIOS when you installed the OS.

   Warning

Changing values in the Windows registry can disable your machine; if you're not sure how to do this please post a question in this tutorial and someone will be glad to help you.

   Note

This method will also work for Windows Vista though the default DWORD string value in Vista will be "4" where it will be "3" in Windows 7.

As a precaution it would be a good idea to create a "System Restore Point" before you start this, the tutorial can be found at the link below.

System Restore Point - Create

Let's get started!
1) In the Windows start menu search box type regedit, right click the entry, click Run as Administrator, enter your user credentials for the UAC prompt, then click yes to open regedit.



2) In regedit navigate to HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services.

3) In the left pane, click on msahci, in the right pane double click on Start to modify it.


4) In the window that opens change the value to 0 (zero), and click OK.

5) In the left pane, click on iaStorV (if there), in the right pane double click on Start to modify it. Repeat step 4, and go to step 6 below.
NOTE: From: Error message occurs after you change the SATA mode of the boot drive

6) Close Registry Editor.
7) Now you'll need to restart the PC and go into the BIOS and enable AHCI. When Windows boots up, it will finish installing the AHCI drivers.



8) You will need one final restart to finish the process after the drivers are installed.

   Note

For those with nForce boards, have a look at the Information post below.

The method was worked out by Everlong and credit for that goes to him, thanks mate!

Enjoy!

Related Tutorials

---

• How to Enable AHCI in Windows 8 and Windows 10 after Installation
• How to Enable HIPM and DIPM for your SSD and HDD in Windows 7

 

[bagavan]

I came across AHCI in my Bios..so there is a slight performance improvement right?

 

[ZaLiTH]

I came across AHCI in my Bios..so there is a slight performance improvement right?

If you see the AHCI option in your BIOS, that means your motherboard supports SATA drives and quite possible the RAID features (AHCI is essentially a RAID function that can be used without requiring a RAID array to be set up).

As to which interface your harddrive uses, check it this way: right-click on 'Computer', select 'Computer Management', on the left select 'Device Manager', and on the right expand the 'Disk Drives' section.

If you could post a screenshot of that window so we can see the harddrive model numbers, we should be able to tell you whether or not your drive is SATA or IDE.

The only other method I can think of off-hand is for you to open your case and look at what cable the drive connects to the motherboard with.


Also, to help us help you, you might want to fill in your system specs, I'd suggest using Speccy http://www.piriform.com/speccyto get the information (it's free and shows a good amount of information).

 

[Bare Foot Kid]

Hello bagavan.





This, in the snip below, is what ZaLiTH is asking for, if yours says "ATA" like mine then you may be able to use this function; also have a look at these articles, at the links below to get a better understanding of some of the functions of the AHCI controller.

Advanced Host Controller Interface

Native Command Queing
click to enlarge

 

[bagavan]

I am posting a screenshot of my hard disk model..

 

[ZaLiTH]

Hello bagavan.





This, in the snip below, is what ZaLiTH is asking for, if yours says "ATA" like mine then you may be able to use this function; also have a look at these articles, at the links below to get a better understanding of some of the functions of the AHCI controller.

Advanced Host Controller Interface

Native Command Queingclick to enlarge
View attachment 89763

Thanks BFK.. I'm at work on my *cough cough* crappy XP machine at the moment. Otherwise I would've put up an example screenshot of that...

I am posting a screenshot of my hard disk model..

I don't even need to Google that one.. Lol. Western Digital Blue drive, 160GB SATA. So, in short; yes, you can use AHCI and yes, you may quite possibly see a small improvement in performance.

One thing I'd suggest, read my comments (and maybe the posts above and below it to get a better idea of the conversation that went on) over here (link). Using AHCI doesn't guarantee a performance boost.

 

[bagavan]

what about raid?is it available?

 

[ZaLiTH]

what about raid?is it available?

That would depend on your motherboard; your motherboard would have to support RAID. You can get your motherboard make and model number from Device Manager as well, or if you get Speccy (link in my post above).

Just keep in mind if you do want to set up RAID, you need at least two drives, the closer they are in make / model / size the better. But to do so, whatever information you currently have on them will be lost when creating the RAID array... So unless you're going to buy two new drives and set up RAID from the start, or have enough space to backup everything to a separate drive, it isn't really too practical to try set it up.

 

[brands]

first off, greetings,

So I followed the steps as mentioned in post 1 BUT when I get to step 4 and despite several restarts, I only see pic1 (installing) without the notes for a restart next to ata channels 1,0,2 and have never seen pic2 in step 4 (driver installation which reads "ready to use")..

I think that I should also mention that when in my bios, the Asus P5KC, although provides a listing for sata configuration, (and the manual notes both IDE and ACHI) ACHI is nowhere to be seen !!! I can only find it in "Advanced device configuration" under the J-Micron eSATA/PATA controller.. which is what I changed and saw some of the drivers being installed..

any assistance would be appreciated..

 

[Dave76]

Welcome to Seven Forums.

According to your Asus P5KC motherboard manual it doesn't support AHCI or RAID only IDE.

Only your J-Micron eSATA/PATA controller has it.

 

[brands]

Hi Dave..
Are you sure, did I misunderstand the following?

 

[Dave76]

Had a hard time finding your manual.

The first time, the AHCI option wasn't there.

Were you able to find it in the BIOS?
At the place in BIOS you posted does it give you a SATA option?

This might be a motherboard version issue or BIOS version issue.

Do you have the last BIOS version installed?

 

[brands]

Nope, the "Configure SATA as" option only gives me the choice of IDE, nothing about ACHI.. Even did a new install of 7 and since I unfortunately could only alter the J-Micron through BIOS did see the previously "hidden" driver installation.. But I'm guessing that since it can't be found in the BIOS (I mean the configure SATA option), it must be related to the J-Micron.

ASUS doesn't provide win7 BIOS for this board,so I went from my original XP64bit to a Vista64 (both were latest versions) hoping that that might do the trick.. but no success.

 

[brands]

OK so I tried out the J-Micron with a fresh install of 7..
HDTune does see the HD as SATA and UDMA6 (which I guess means that everything is working fine) but the results simply don't justify the whole fuss. (identical if not worse than those while on IDE and of course worse than how I've seen the HD perform on various online reviews)

I'm guessing that I must have missed some really obvious setting that I shouldn't have.
Any help appreciated.

 

[ZaLiTH]

OK so I tried out the J-Micron with a fresh install of 7..
HDTune does see the HD as SATA and UDMA6 (which I guess means that everything is working fine) but the results simply don't justify the whole fuss. (identical if not worse than those while on IDE and of course worse than how I've seen the HD perform on various online reviews)

I'm guessing that I must have missed some really obvious setting that I shouldn't have.
Any help appreciated.

Dave76 had a valid point earlier; while the JMicron JMB363 controller itself supports SATA / AHCI / RAID, you specific motherboard chipset may not make use of all that controller's features.

The manual appears to be wrong as it refers to RAID which the ICH7 can not support.[/quote]So, I would highly recommend getting SIW and having a look at the exact chipset setup you're running on that board.

 

[futureaviator]

Hi I have a asus p5qpl-vm epu motherboard, I followed all the steps. When I get to BIOS I can't find the AHCI. Where can I find this?

Thanks

 

[Bare Foot Kid]

Hello futureaviator, welcome to Seven Forums!





I have a P5Q Pro and this is where AHCI is for my board.



click to enlarge

 

[brands]

Hi ZaLiTH
Well the P5KC doesn't have an ICH7 but an ICH9 which can support AHCI so I really can't say what the issue with the J-Micron was, but anyway, all's well since I finally got around it..
I read in the ASUS forums about AHCI being disabled/removed from P5KC BIOS.. so after some reading, I crossflashed the P5KC with Kokakey and gave the mobo P5KR BIOS and by doing so got AHCI
The only issue now seems to be that the Ethernet port, while fully functional, won't let me connect to the internet.. but I guess that that's a whole differet thread.

Thanks for all the help.

 

[Dave76]

Good news you found the solution to the AHCI problem.

Thanks for letting us know.

 

[futureaviator]

Thanks BFK.

This is what I see in my BIOS. Do I need to update my motherboard?

 

[Bare Foot Kid]

Thanks BFK.

This is what I see in my BIOS. Do I need to update my motherboard?

Hello again.



You could see if "Configure as AHCI" will be offered in a BIOS update, you are aware of the hazards a BIOS update present correct?