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

 

[MikeM12345]

Nope nothing in device manager, I am ready to do a clean install of win 7 with my bios AHCI option enabled.
Any suggestions or tips. As you can tell from my sys spec I am running Asus and AMD

 

[ZaLiTH]

Nope nothing in device manager, I am ready to do a clean install of win 7 with my bios AHCI option enabled.
Any suggestions or tips. As you can tell from my sys spec I am running Asus and AMD

To be honest, if you enabled AHCI in your BIOS and then managed to boot into Windows without any issues, then I'd say it's working... :/

Another way to check is via the 'Safely Remove Hardware' icon in your systray. Using AHCI will enable hot-swap support for all drives in your PC, so you should now see your internal drives in that list as well.

Besides, I highly doubt you'll see enough of an improvement switching to AHCI to warrant a format and reinstall... I posted (earlier in this thread I think) about how I found AHCI to make a bigger difference to drives with more fragmentation due to it's NCQ method of reading/writing data.

 

[Windows7Nubie]

I am just starting out with Win 7 32 bit. Attached are files showing HDTune results for IDE setting and AHCI setting. The IDE setting appears to be faster. It may be that I am not setup right or that my new hardware may have a problem. But if all is okay, take the advice given earlier in the post and stick with IDE for a regular drive.

 

[ZaLiTH]

I am just starting out with Win 7 32 bit. Attached are files showing HDTune results for IDE setting and AHCI setting. The IDE setting appears to be faster. It may be that I am not setup right or that my new hardware may have a problem. But if all is okay, take the advice given earlier in the post and stick with IDE for a regular drive.

To quote from an older thread that covered this topic pretty well:

There is no performance difference to IDE or AHCI because they are only communication protocols. The actual physical SATA connection is what determines the speed. Not whether you are using IDE or AHCI. IDE and AHCI will preform the same because the SATA connection is the same speed regardless.

You can read the thread here if you like, it's a very interesting and informative when it comes to AHCI vs IDE, focussing mainly on the performance side..

 

[ICIT2LOL]

Thanks TBK that was just amazing for an old codger like me - am thinking of slipping an SSD into my Toshiba laptop and was not sure if I could get this going after install.

Wow I shall be able to get rid of all the junk

 

[ICIT2LOL]

One small query I checked in regedit tonight and the ACHI value is set to (3) yet in the BIOS the setting is ACHI .

Now I am a little confused as to which one is correct?

 

[Koyuki]

Oke so I've tried this several times without luck so I decided to register and ask for some help.

1. These are the default settings of my motherboard. Setting the top ''ICH SATA CONTROL MODE'' to AHCI and reboot the following happens:

You can see the HDD listed.. and then a messege that says there is no supported driver, please insert one and press a key...

2. If I set ''ONBOARD SATA/IDE Ctrl Mode to AHCI and leave the top to IDE it does boot (just doesnt find and drives) installs 2 drivers but its still in IDE mode.

3. If I set both settings to AHCI the first thing still happens where I cant boot into windows.

Does anyone have any idea on how to solve this problem? Cheers!

 

[Fejinwales]

These may be a dumb questions but I need to ask them anyway, please forgive my ignorance. I just bought a Cruical SSD which is going to replace the old HDD (C:\) in my PC. I intend to leave the old disk in these but disconnected in case of probs). Anyway.

Is my motherboard - ASUS P6T Deluxe one of those nForce boards?

If I enable AHCI in the BIOS before installing the OS will I still need to do the registry thing or any other settings after install? - I believe not but need to be sure.

Also do I enable AHCI before connecting the SSD or afterwards - but before I begin installation of the OS onto it? (boot into BIOS as soon as it is connected).

Finally, and this is important for me as I get bad luck. Should this SSD fail and I have to revert back to my old HDD (left in there), Will I simply have to go into the BIOS before re-connecting it and enable SATA again? from which point it will boot from the old HDD as before?

Thanks for the time taken to read this.

 

[ICIT2LOL]

These may be a dumb questions but I need to ask them anyway, please forgive my ignorance. I just bought a Cruical SSD which is going to replace the old HDD (C:\) in my PC. I intend to leave the old disk in these but disconnected in case of probs). Anyway.

Is my motherboard - ASUS P6T Deluxe one of those nForce boards?

If I enable AHCI in the BIOS before installing the OS will I still need to do the registry thing or any other settings after install? - I believe not but need to be sure.

Also do I enable AHCI before connecting the SSD or afterwards - but before I begin installation of the OS onto it? (boot into BIOS as soon as it is connected).

Finally, and this is important for me as I get bad luck. Should this SSD fail and I have to revert back to my old HDD (left in there), Will I simply have to go into the BIOS before re-connecting it and enable SATA again? from which point it will boot from the old HDD as before?

Thanks for the time taken to read this.

Hiyya FejinWales welcome

Look mate no expert but my BIOS was set to ACHI before with my HDD's and I just left it as is the SSD went perfectly all I had to do was do the firmware update (0309) for the Crucial M4 128GB I put in and again I am no expert but I don't think you would have to reset the BIOS should the SSD fail -it won't mate anyway.

But I guess the real deal fellows will correct me if I am wrong.

Nice to meet someone from the old country too

 

[Fejinwales]

Hi ICit2lol..

G'day mate. OK then, I shall set it to ACHI and do my damnedest to get it working. The reason I was concerned about the SSD failure was that quite a few people had failures with the OCZ drives, a firmware issue apparently when Windows shuts down and tells it to sleep, it stayed asleep and that was that. My nephew suffered this with one of their drives. This is why I could a Crucial as they - seemingly - do not have this issue. But I have shitty luck and if something's gonna go wrong it'll go wrong for me.

I'd love to visit OZ, some of my friends have moved out there, some in Surfers paradise - Gold Coast, one in Rathmines N.S.W, another in Melbourne.

Anyway, thanks for the advice, I am off then to do battle.

 

[noprob]

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[Fejinwales]

Hi Bare Foot Kid, thanks for the tutorial, I have it all down and ready to carry out.

I chickened out in the beginning and in the end I decided to do the Vista 64bit install on standard BIOS settings just to make sure I had a nice clean install of my OS and all my software, configured and updated that I know I could fall back on. With the sort of luck I have with computers I needed this fall-back; believe me! I've now made an Acronis image and backed it up onto an external and am considering the option of activating AHCI in the Registry then BIOS.

I know this is a Windows 7 Forum but the result should be the same for Vista 64-bit, besides my nephew, who has the same Crucial SSD does run W7 Ultimate, and he wants to know as well.

I have a query to all the W7F users who have tried this.
I am wondering if I will have a great enough improvement in performance by enabling AHCI given my system (if you can see my specs) to make it worthwhile. Or are there other, more subtle improvements to gain my enabling it?

Any comments on this? Especially from those who have done this already?

Any answer would be welcomed and greatly appreciated.

 

[ICIT2LOL]

Hi ICit2lol..

G'day mate. OK then, I shall set it to ACHI and do my damnedest to get it working. The reason I was concerned about the SSD failure was that quite a few people had failures with the OCZ drives, a firmware issue apparently when Windows shuts down and tells it to sleep, it stayed asleep and that was that. My nephew suffered this with one of their drives. This is why I could a Crucial as they - seemingly - do not have this issue. But I have shitty luck and if something's gonna go wrong it'll go wrong for me.

I'd love to visit OZ, some of my friends have moved out there, some in Surfers paradise - Gold Coast, one in Rathmines N.S.W, another in Melbourne.

Anyway, thanks for the advice, I am off then to do battle.

Glad you got it sorted I knew you would get pointed in the right direction.
Um yeah mate you would probably feel right at home at the moment - wet as all hell! LOL!!

Got to do battle myself tomorrow with an SSD into a laptop :shock:

 

[CannibalKid]

Hi,

I've followed the directions up to step 4. I've changed the BIOS but then when I reboot, it goes to load the OS but says "no bootable partiton in table". I can get my computer to load the OS again by restoring the defaults in the BIOS.

Any ideas why this happens?

 

[Ton]

I just found this tutorial and tried to follow the instructions to enable AHCI for my Asus P5B motherboard.
Unfortunately it didn't work. After editing the registry I rebooted, enabled AHCI in BIOS and rebooted again. Then my screen freezes, telling me that AHCI port is not detected. I can't do anything anymore. No possibility to enter BIOS setup or Windows.
By clearing CMOS and resetting BIOS to default I could get my pc working again and fortunately I had made a system image before and could restore from that.
Do you have any idea why I can't get it working or what I could have done wrong ?
Thanks in advance.
Ton

 

[d0m0]

Thanks a lot, I was thinking of reinstalling my OS to enable AHCI... you just saved me a lot of hassle !

 

[ICIT2LOL]

Hiyya BFT my tester machine which has an Intel DG43NB board has the capabilities of running ACHI, EUFI, and 32 or 64bit functions.

Now I have just installed an SSD to it and BIOS has it currently is running 32bit & IDE now my small query is that I also have an 80GB HDD that was the original HDD and install if I change the IDE to ACHI am I going to have problems with the older HDD?

Alternatively I have another 64bit OEM would you recommend me installing that after cleaning up both drives and then changing the 32bit to 64bit in the BIOS and the IDE to ACHI? Will I be gaining much in performance?

I only ask as the HDD is a fairly old 2005 Seagate (3Gbs SATA) as I don't want to do anything to wreck this really nice (and given to me free) board / machine which is currently booting faster than my Sandy Bridge build with an SSD and ACHI! Or I can just get another newer HDD if that is what you say would be better. Cost is not really an issue but all the same I would rather just keep the small HDD.

 

[lilmoja]

Can I still do this even if I installed windows for like 4 months now?

 

[Brink]

Hello lilmoja,

If you already had AHCI enabled in the BIOS when you installed Windows 7, then there would be no need to. However, yes you can do this tutorial anytime after installing Windows if needed.

 

[ICIT2LOL]

Well I did the tutorial but didn't get the messages but it has load the ACHI but the boot is much longer now with a black screen before the OS cuts in - have I done something wrong?