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

 

[Brink]

Hello M1GU31,

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.​

Hope this helps,
Shawn​

 

[bigpygme]

thanks for the tutorial -
i am baffled by how to load/install the AHCI drivers i downloaded from Asus for an M4A89GTD Pro/USB3 board..
i've tried with Device Mgr but i can't get them to install. i have Asus x64 cat, inf and sys files on a thumb drive.

too bad - i know how to change the BIOS configuration to AHCI, but of course without the drivers installed the cursor just blinks at me when i try to boot ... so i go back to IDE.

i'd love to solve this , any help appreciated.

Michael

 

[FliGi7]

I currently have 3 SATA HDD's configured as IDE in my BIOS. One for the OS and two storage. I'm looking to transfer my OS over to my new SSD. In the BIOS, I can't designate the SSD as AHCI without it changing all of my SATA drives to AHCI. Should there be a way to designate only the SSD as AHCI or do I have to let it change all of the drives to that? If so, will this hurt anything and how do I go about doing this safely?

Would it be easier/better to change the BIOS to AHCI and reinstall Win7 on the SSD? Or can I move the OS to the SSD (using Paragon's Migrate OS to SSD) using the current SATA configuration as IDE, change the appropriate registry settings in Windows to AHCI, then reboot and change the BIOS to AHCI?

 

[Dave76]

The AHCI setting will be for all drives.

It won't hurt anything, you might see an improvement in HDD performance.
I would recommend it.

 

[FliGi7]

The reason I ask is because of the warnings of changing AHCI and possibly getting BSOD's and data failures. However, I want to make sure that won't happen with my storage drives. They are far too important.

 

[bigpygme]

Hi all -
i was very excited to read that you CAN install.run AHCI after installing Win7 ... and am eager to try it

BUT

step 4 in the tutorial on page 1 did not work for me.

4) 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.

it didn't.

does anyone have any help with how to use device manager or some other method to install the AHCI drivers? i'm not sure what i'm doing wrong ...

as i have mentioned, i have Asus x64 ahci.cat, .inf and .sys files on a thumb drive ready to go - but HOW ? is the ahci.sys driver the only one i need to worry about? how do you get it to install? Windows says my drivers are up to date, and when i select these files, it won't install these files using Dev Mgr ...

thanks for your time and expertise ...

Michael

 

[FliGi7]

Changed over to AHCI from IDE just now. My main OS drive is a 150GB WD Raptor SATAII. No change in WEI score (still 5.9) and transfer speeds went down about 3-4% across the board (except for 4KQD32 Read) in CrystalDiskMark. Meh. Didn't really expect anything, but would have been nice.

 

[seekermeister]

I wouldn't expect an improvement in the WEI score, because it always rates based on the device with the lowest score., which is not likely to be the hard drive.

EDIT: I was wrong, I have exactly the same WEI score as you do, and after checking the lowest score is the hard drive, but I doubt that would change much, unless one had an SSD.

 

[FliGi7]

I thought I had read it improved some people's WEI, but wasn't sure. Anyway, not too worried about it, just didn't do much for me, and might have even set things back a few notches. Nothing noticeable, though.

 

[seekermeister]

For what it's worth, I'm currently in the process of setting up AHCI myself. As far as I can tell, there is no noticeable improvement in the general OS function, except that it does seem to boot a little faster than before.

 

[streetwolf]

I've been trying to narrow down a problem I've been having with restoring a disk image of my SSD in a standalone environment, namely a recovery disk or USB stick. I have the controller defined as AHCI in my BIOS. Restores which used to take minutes can now take hours. Looking through different posts on the Web I've seen reports of the same problem. Many people claim that setting the controller to IDE in the BIOS and then rebooting to your particular standalone restorer fixed the speed issue.

I haven't tried this yet but will when I need to do a restore. Just wondering if I can get verification of this from the resident Gurus here?

 

[dbseven]

This is what I got from my motherboard maker support:

To install AHCI drivers properly (required for hot swap):
1. Enable AHCI mode in BIOS (under chipset – southbridge).
2. Format the hard drive.
3. Boot to CD, to Install Windows.
4. During the installation Windows will not recognize any drives, and will prompt you to install the third party AHCI drivers.


[email protected]
626-581-1055 menu select 2

​

This email message is for the sole use of the intended recipient(s) and may contain confidential information. Any unauthorized review, use, disclosure or distribution is prohibited. If you are not the intended recipient, please contact the sender by reply email and destroy all copies of the original message.

From: [email protected] [mailto:[email protected]]
Sent: Monday, February 13, 2012 4:11 PM
To: [email protected]
Subject: << BIOSTAR Technical Support Request FORM >>


=================================================
Question:
How to install AHCI (SATA HOT-SWAPPABLE) drivers in Windows 7 x64?
=================================================
Email:
[email protected]
Model / BIOS / PCB:
790GXE / /
OS:
Win 7 x64
Name / Country / Local Dealer:
Donald Bock / USA /
CPU:
AMD
Memory / Speed & Size:
/
VGA Brand / Model:

HDD / Size:
/
Power Supply:

Other Device:

=================================================

Will the above AHCI work as described or do I need to do what Biostar Support wrote?

I have NOT enabled AHCI in BIOS yet; this install of Windows 7 was STRAIGHT OFF.

To give a heads up, would you mind giving EXPLICIT details? Thanks. Donald.

 

[Dave76]

If you follow the tutorial it will work just fine.
The tutorial is Explicit details.
Many have already done this with no problems.

If you are, going to or want to, re-install your OS you can do it that way also.

 

[sry9681]

Already at 0

Can I still proceed with the process of turning the mode to AHCI? on Regedit, it was already at 0. sorry if its a repeated comment.

 

[ZaLiTH]

Can I still proceed with the process of turning the mode to AHCI? on Regedit, it was already at 0. sorry if its a repeated comment.

The 'start' entry in HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services simply enables the AHCI driver in Windows 7 or Vista (source). So if it was already on 0, you shouldn't have any need to change it.

In this case, I'd recommend a backup with your favourite backup software (or if you don't have any, create a fresh Restore Point), then go into the BIOS and try enable AHCI. If it fails to boot, then we can start looking at why.

 

[sry9681]

I was able to get into the BIOS after a good week of windows 8 not letting me. Aparently i bought this computer with AHCI mode on. well that is a relief! thank you anyway!

 

[ZaLiTH]

I was able to get into the BIOS after a good week of windows 8 not letting me. Aparently i bought this computer with AHCI mode on. well that is a relief! thank you anyway!

Windows shouldn't have anything to do with you accessing the BIOS, it's loaded before the OS... But either way, glad you figured it out.

 

[dbseven]

Yes, true, Windows 7 and Vista can find the AHCI drivers to LOAD BEFORE OS startup; it jut looks funny with a black text screen showing Loading AHCI driver...then Windows finishes boot.
- dbseven

 

[MikeM12345]

I have enabled AHCI in bios and reg. HOW or WHERE can a actualy see the AHCI driver, have looked in device manager nothing ?

 

[Dave76]

Welcome to Seven Forums MikeM12345.

In Device Manager expand the 'IDE ATA/ATAPI controllers' you should see something with '...AHCI Controller' listed.