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

 

[futureaviator]

Hey BFK

I'm aware of the dangers associated with AHCI. I've been trying to find the BIOS update but haven't so far. If possible could you please send a link to update my BIOS.

Thanks

 

[ZaLiTH]

Hey BFK

I'm aware of the dangers associated with AHCI. I've been trying to find the BIOS update but haven't so far. If possible could you please send a link to update my BIOS.

Thanks

There aren't any dangers with AHCI, BFK was talking about the potential dangers of a failed BIOS update. Just make sure you get a BIOS for your exact motherboard and make sure your PC doesn't lose power half way through the update. It's not likely to happen as the flashing process doesn't take that long on any motherboard.. But if you have access to a UPS it'll be safer.

If you go to the Asus site (ASUSTeK Computer Inc.-Support-), type in your motherboard model number in the top left (where it says "Input Model to Search") then select BIOS from the category just below that, you'll get to the downloads. Took me about 2 minutes to find the list of BIOS files..

 

[shanouser]

the easy way when nothing else works:

1. backup your windows7 drive (as drive image) to external drive
2. make windows7 recovery cd
3. burn ahci drivers to another cd
4. boot from the recovery cd and choose the "add drivers" option
5. add the ahci drivers from the cd
6. just restore your windows installation, this time with fully working ahci
7. enjoy

 

[wakeboardr116]

the easy way when nothing else works:

1. backup your windows7 drive (as drive image) to external drive
2. make windows7 recovery cd
3. burn ahci drivers to another cd
4. boot from the recovery cd and choose the "add drivers" option
5. add the ahci drivers from the cd
6. just restore your windows installation, this time with fully working ahci
7. enjoy

Thank you! This way finally worked for me! Only one problem though. I ran the SSD benchmark again and now my scores were worse this time. Especially the Write scores. Any one know how this could be???

 

[vanquish46]

Hello W7 Forums!

I have gone through about half of this thread and spent time on google, but all to no avail. I previously had my eSata port (and thus AHCI) working with a previous install of Windows 7 Pro x64. Unfortunately, my 8800 GT died, and corrupted my W7 install with it. After replacing the PSU and GPU I proceeded to reinstall W7.

This is where the problems started. I don't remember exactly what happened, but it should be ok. I had trouble installing, and must have had to disable AHCI in BIOS for the install to complete (otherwise the AHCI should be working). I have now edited the registry, changing the value to '0'. I turned AHCI on (it is called RAID autodetect, if that is relevant), saved the new settings and let it boot. It just proceeds to loop through the beginning steps, once it says Windows 7 and the dots begin to appear it restarts the boot process. It does this a few times and then tells me W7 can't start due to a recent hardware/software change and asks to a)repair b) proceed as normal. I chose b and simply disabled AHCI in my BIOS, and it continued to boot as normal (no data loss or anything).

I'm assuming it's stuck in the boot loop because there are no AHCI drivers, and thus it can't detect my HDD. Hopefully someone knows what I can do. I think I may be able to use the W7 retail disk for the drivers, but I'm unsure how to have the system get them from the disk.

Thank you for your help .

EDIT:
I am hesitant to just attempt a reinstall because of the issues I had last time when installing. I think I will just run into them again. Also besides the hardware changes, nothing else was changed. I am sure I plugged all cables back in correctly. The only other change was switching a SATA cable.

 

[wakeboardr116]

Hello W7 Forums!

I have gone through about half of this thread and spent time on google, but all to no avail. I previously had my eSata port (and thus AHCI) working with a previous install of Windows 7 Pro x64. Unfortunately, my 8800 GT died, and corrupted my W7 install with it. After replacing the PSU and GPU I proceeded to reinstall W7.

This is where the problems started. I don't remember exactly what happened, but it should be ok. I had trouble installing, and must have had to disable AHCI in BIOS for the install to complete (otherwise the AHCI should be working). I have now edited the registry, changing the value to '0'. I turned AHCI on (it is called RAID autodetect, if that is relevant), saved the new settings and let it boot. It just proceeds to loop through the beginning steps, once it says Windows 7 and the dots begin to appear it restarts the boot process. It does this a few times and then tells me W7 can't start due to a recent hardware/software change and asks to a)repair b) proceed as normal. I chose b and simply disabled AHCI in my BIOS, and it continued to boot as normal (no data loss or anything).

I'm assuming it's stuck in the boot loop because there are no AHCI drivers, and thus it can't detect my HDD. Hopefully someone knows what I can do. I think I may be able to use the W7 retail disk for the drivers, but I'm unsure how to have the system get them from the disk.

Thank you for your help .

EDIT:
I am hesitant to just attempt a reinstall because of the issues I had last time when installing. I think I will just run into them again. Also besides the hardware changes, nothing else was changed. I am sure I plugged all cables back in correctly. The only other change was switching a SATA cable.

I have an XPS 430 (pretty much the same as the 420) and was having the exact same problem. The only way I finally got it to work was following the steps shanouser posted just above this.

Make a system image to an external HDD
Make the win 7 recovery CD if you dont already have one
Burn the latest AHCI driverrs onto a CD (I got the most recent ones from the Intel site)
Go into BIOS and change the SATA settings to RAID ON
Boot to the recovery CD and choose to restore system image
Select the add drivers option and load the AHCI driver from the CD
Continue to restore windows from the image

This is what finally worked for me.

 

[vanquish46]

Thank you! I will try that and post an update if I can get it to work.

EDIT:

Is the

2. make windows7 recovery cd

the "System Repair Disc" I will be prompted to make after backing up my disk image? Or is this something else I am unaware of?

Also @ wakeboardr116 is http://downloadcenter.intel.com/Detail_Desc.aspx?agr=Y&DwnldID=18859&lang=eng what you used?

 

[wakeboardr116]

Thank you! I will try that and post an update if I can get it to work.

EDIT:

Is the

2. make windows7 recovery cd

the "System Repair Disc" I will be prompted to make after backing up my disk image? Or is this something else I am unaware of?

Also @ wakeboardr116 is  Intel(R) Rapid Storage Technology what you used?

Yes the system repair disk is the same as the recovery cd I believe.

Edit: Yeah I believe that link is the right one for the drivers.

 

[wakeboardr116]

Here I still have the zip file containing the drivers from when I did it. Just extract all the files and burn them directly to a CD.

View attachment f6flpy96x64.zip

 

[Dave76]

vanquish46,

Windows 7 can't start due to a recent hardware/software change and asks to a)repair b) proceed as normal

Put the Raid drivers on a CD or USB stick.

Select 'repair' and follow instructions, look for the option to install drivers.

How to load SATA driver when using Shift+F10 to open an Command Prompt on Windows 7 or Vista DVD


How to Load SATA Drivers in Windows System Recovery Options​

​

You can make a system repair disk but, must be done from within windows.

How to Create a Windows 7 System Repair Disc


Hope these tutorials will help you.​

 

[DirtyElf]

i dont need to do this tutorial to enable AHCI if i enabled it in my BIOS before i installed windows 7 correct? how can i be sure that it is activated?

 

[wakeboardr116]

i dont need to do this tutorial to enable AHCI if i enabled it in my BIOS before i installed windows 7 correct? how can i be sure that it is activated?

If you enabled it in the BIOS before installing then it should already be set. If you want to double check go to device manager and click on storage controllers and it should say something like SATA RAID controller.

 

[Bare Foot Kid]

Hello DE.



Here's what mine looks like.

 

[DirtyElf]

ok ill check when i get home, thanks

 

[DirtyElf]

it appears my AHCI is functioning correctly... right?

 

[wakeboardr116]

Appears so.

 

[Bare Foot Kid]

it appears my AHCI is functioning correctly... right?

Well done mate.

 

[ZaLiTH]

Here's some food for though (been a while since I did one of these posts... lol), I've seen a few posts on blogs and other forums in response to people asking "should I use IDE / AHCI / RAID...?" that suggest going straight for RAID, even if there's no RAID arrays.

Essentially, AHCI is RAID without the striping or mirroring features. Whether or not that is true across the board or only with the more modern controllers is beyond me, but considering the fact that both have been around for long enough to be a commonplace, I'd say that's a safe assumption.

So, based on that theory, to 'future proof' a build, wouldn't it actually make sense to select RAID even if there are no arrays? That way, if a PC owner descides to set up a RAID array later (as opposed to actually planning to), it'll be much easier and won't require any reinstalling or altering the OS...

 

[Dave76]

The problem occurs when you try to switch from IDE to either RAID or AHCI.

Actually RAID is a function of AHCI, when you select RAID it uses AHCI and therefore has it's functions.

It's generally advised to use RAID settings before you install your OS, this will cover you for all scenarios, and will work with one or more HDDs and/or SSDs as separate drives. These can be set to RAID mode if the prerequisites are met.

 

[ZaLiTH]

The problem occurs when you try to switch from IDE to either RAID or AHCI.

I am quite aware of that, thanks Dave. I actually used this very tutorial to change my system a few months back.

Actually RAID is a function of AHCI, when you select RAID it uses AHCI and therefore has it's functions.

Maybe I'm nit-picking, but isn't RAID technology older than AHCI mode...? Although, I suppose if you look at what the acronyms stand for, that is actually correct. Damn the computer world... So confusing, yet so simple at the same time.

It's generally advised to use RAID settings before you install your OS, this will cover you for all scenarios, and will work with one or more HDDs and/or SSDs as separate drives. These can be set to RAID mode if the prerequisites are met.

In all honesty, I'd never really seen much about that until I specifically went looking for it.. Found a few very interesting reads on that topic though.