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

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• 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

 

[Night Hawk]

That was more a generalized statement on sata controller driver sets not individual drivers since you would simply go to the board manufacturer's own support site for the various updates if not found in the MS optional. Asrock should have the AHCI driver available at their support site. ASRock > Products > Motherboard > 880GM-LE > Download

 

[dwarfer66]

I was looking at doing this on my previous rig, but on my new rig I built yesterday, ACHI was automatically chosen for me. I am not using an SSD drive for my boot (look at specs).

 

[Night Hawk]

With the board here I had just seen a clean install of 7 go on and simply made the setting change and watched as everything went through the motions automatically with a prompt to restart once Windows finished up. The funny thing was seeing both Sata II drives installed as SCSI devices while a pair of Sata III drives still remain in the Native ide mode.

So far everything has been running smouth while it did add a few seconds onto the post tests as the two OS drives are now being listed separately from the other pair. The mode is actually an old performance method used back in the 90s when businesses would see SCSI arrays created for boosting access times with storage drives. Often those are still seen available as external as well as internal setups.

 

[OvenMaster]

After running my screen capture software (HyperCam2) this morning and getting massive 30-40 second delay's worth of audio sync in the resulting .avi files, reverting to IDE mode in BIOS and M$ IDE drivers for all drives cleared up the problem.

Looking carefully through AMD's driver packages, I was a bit surprised to find only AHCI and RAID drivers for Win 7, but nothing for IDE or IDE-compatible SATA. Guess M$'s generics are "good enough".

 

[Night Hawk]

I would think the Asrock support page's sata controller and other updates would have what you need there. Those are typically bundled driver sets since anything ide is controlled through the board itself.

As far video captures here I've captured in avi as well as mpeg II in either the Native ide mode used for 2yrs. and then lately switching to the AHCI mode and not one problem. I suspect the screen capture program itself has it's own needs and why it refused to work for you.

Performance wise in general I would have to say I haven't been seeing any great performance boost in either mode having just seen a clean install of Windows. That alone cleaned up a lot of clutter from the previous install. The transition went smooth however with no hiccups seen so far.

 

[OvenMaster]

I would think the Asrock support page's sata controller and other updates would have what you need there. Those are typically bundled driver sets since anything ide is controlled through the board itself.

As far video captures here I've captured in avi as well as mpeg II in either the Native ide mode used for 2yrs. and then lately switching to the AHCI mode and not one problem. I suspect the screen capture program itself has it's own needs and why it refused to work for you.

Performance wise in general I would have to say I haven't been seeing any great performance boost in either mode having just seen a clean install of Windows. That alone cleaned up a lot of clutter from the previous install. The transition went smooth however with no hiccups seen so far.

I did go to the ASRock page and downloaded the All-In-1 driver package. Unzipping it and looking through the drivers shows that only AHCI and RAID drivers are included. There simply are no IDE or PATA drivers from AMD for my SB710 chipset offered, even as far back as the ASRock package from April 2010. I can't find any anywhere, even on AMD's site, after searching for four days, either.

Using AHCI, the only improvements that were noticeable was a very slight speed increase when moving or copying files from one HD to another. But when using my screen capture software, I did notice that the HD light stayed on continuously. In IDE mode, the light would go "blip...... blip......blip....." about every three seconds. *shrugs*

If I ever have to reinstall Windows 7 (God forbid), I'll try the AHCI install route from scratch, but until then, sticking with IDE mode works best for me.

 

[Night Hawk]

The software I run here of course goes along with the tv tuner/capture card where I was running into burn to disk problems until sticking an old cd burner in and whamo it worked. The same for the newly clean install of 7 set for the Native ide and automatically configuring itself well when switching to AHCI.

The part about seeing a continuous HD led busy all the time shows you may have a program glitch to tend with since it is taking up the cpu time as well as wanting to write to the drive but unable to. It usually turns out to be some problem with the present install of a program rather then the mode the drives are run in or the type of drive you have.

 

[azkicker1970]

Dell Precision 670

I have an SSD coming for my son's Dell Precision 670. It's running 64bit win 7 pro. It have 8 gigs of ram and I will be installing OCZ Agility 3 AGT3-25SAT3-180G 2.5" 180GB SATA III MLC Internal Solid State Drive (SSD) once it arrives. I have read that the ahci needs to be enabled but don't see it in the bios. Can anyone tell me if this SSD drive will work as designed? Is this tutorial exactly what I'll need? I will be using this as his primary drive and a 150 gig sata drive as his pictures and songs drive. I will also be installing this video card in the next few weeks. ZOTAC AMP! ZT-50302-10M GeForce GTX 560 Ti (Fermi) 1GB 256-bit GDDR5 PCI Express 2.0 x16 HDCP Ready SLI Support Video Card. Any advice anyone can give me would be appreciated.

 

[Night Hawk]

The board on that model includes a SCSI connector I see. "11 SCSI connector (SCSI)" 11 is Item #11 seen in the general information seen at Documentation

If you scroll about half way down the Dell support page under "Ssytem Setup Options" you will see which options in the bios setup deal with the AHCI under SCSI there on the page seen at Documentation

The first is "SCSI Controller Available on the Dell Precision 670 computer.This field enables and disables the integrated SCSI controller."

The second to note is "SATA Operation Configures the operating mode of the integrated hard drive controller." This is where to look for the mode settings while the first would be for enabling or disabling the onboard SCSI ccntroller for the main connector.

 

[HoneycombAG]

I don't have options for AHCI in BIOS. Is it turned on by default?

The southbridge chipset reads "MCP61".

 

[Night Hawk]

The manual for the board itself will show what options are present. Generally you don't go into the bios setup and see a separate AHCI tab. You have to get familiar with the layout and hard drive options and go in further to find out just where that option if present is located.

Here I have the feeling the board saw that or another default drive setting enabled since the initial clean install of 7 when new wouldn't load up! When going back into the bios setup and switching over to the Native ide mode 7 then loaded right up until just lately changing to AHCI where 7 automatically adjusted to it.

Still the best place for bios settings would be in the user manual or support site's documentation for that make and model board. That's what you will need to go by anyways.

 

[Solarstarshines]

The manual for the board itself will show what options are present. Generally you don't go into the bios setup and see a separate AHCI tab. You have to get familiar with the layout and hard drive options and go in further to find out just where that option if present is located.

Here I have the feeling the board saw that or another default drive setting enabled since the initial clean install of 7 when new wouldn't load up! When going back into the bios setup and switching over to the Native ide mode 7 then loaded right up until just lately changing to AHCI where 7 automatically adjusted to it.

Still the best place for bios settings would be in the user manual or support site's documentation for that make and model board. That's what you will need to go by anyways.

Nightawk is right also if you have Bios and support downloads for that board and they support achi and raid drivers then your board does

I have a AM2+ board that has achi but the settings are hidden not every board makes them easy to see

 

[Night Hawk]

Just take a fast look at the Dell documentation pages I posted back in Post #468 to how well hidden that for the other system. That still didn't name AHCI or ide but simply indicated one sub section for sata settings. Buried deep is probably how to describe that one.

This is one reason I prefer to read through the manual that comes with any new board first off to know just what I will be running into for anything. Gettting to know your way through the bios with a manual to reflect back on will be a great help.

Well at least for a ful atx model board at least over the micro atx mb in a new mini tower case here I'm working on. The only thing outlined for sata was best seeing a matching pair and then going into creating an array which is the 3rd drive mode option on most newer boards. The main board however sees 6 Sata II and another pair of Sata III ports where there are also more options to find in the larger bios version used.

 

[OvenMaster]

The software I run here of course goes along with the tv tuner/capture card where I was running into burn to disk problems until sticking an old cd burner in and whamo it worked. The same for the newly clean install of 7 set for the Native ide and automatically configuring itself well when switching to AHCI.

The part about seeing a continuous HD led busy all the time shows you may have a program glitch to tend with since it is taking up the cpu time as well as wanting to write to the drive but unable to. It usually turns out to be some problem with the present install of a program rather then the mode the drives are run in or the type of drive you have.

Are you basically saying, then, that I should uninstall the program in my present IDE mode, make the necessary Registry and BIOS adjustments, and after rebooting, reinstall and test my program? Just confirming.

 

[Night Hawk]

The software I run here of course goes along with the tv tuner/capture card where I was running into burn to disk problems until sticking an old cd burner in and whamo it worked. The same for the newly clean install of 7 set for the Native ide and automatically configuring itself well when switching to AHCI.

The part about seeing a continuous HD led busy all the time shows you may have a program glitch to tend with since it is taking up the cpu time as well as wanting to write to the drive but unable to. It usually turns out to be some problem with the present install of a program rather then the mode the drives are run in or the type of drive you have.

Are you basically saying, then, that I should uninstall the program in my present IDE mode, make the necessary Registry and BIOS adjustments, and after rebooting, reinstall and test my program? Just confirming.

I doubt switching back from AHCI to ide has anything to do with the problems you are running into with it. You had mentioned the HD led being left busy all the time which indicates the program was still trying to write to the drive but could not finish the task.

Generally the two main causes are hardware like I found here was 1) hardware where two working dvd burners no longer would work or 2) a software problem where a good clean reinstall of the program may simply clear things up provided nothing else is interfering.

Looking at anything new added on recently which is now cause for concern if everything with the program itself is still working as it should could explain a few things. A new program seeing a startup service running in the background causing problems for you.

The last item to consider would be a background service found to be disabled or set for manual while a program needs it set to automatic. A look at the FAQs section at the software company's support site might point out which service to look at when seeing problems as part of the troubleshooting process.

 

[OvenMaster]

Okay, understood.
I went ahead and uninstalled my screen capture program, edited the msahci Start value to 0 in the Registry, rebooted into my BIOS, set it to AHCI, rebooted, then reinstalled the screen capture program.
I'll be eternally damned.... no more issues. No solid hard drive light, and no 30-40 second audio sync problems.
You were right... it was the program install.

I also had run HD Tach on all my hard drives with IDE drivers and then with AHCI drivers for a crude benchmark.
There was zero difference in maximum read speeds on any SATA hard drive.
There was no difference in random access times.
There was a reduction in burst rate by about 3MB/sec when AHCI was used.
Drive 0 - 205.1MB/sec (IDE) vs 202.5MB/sec (AHCI)
Drive 1 - 198.0MB/sec (IDE) vs 195.7MB/sec (AHCI)
Bottom line: no improvement by activating AHCI for my mechanical hard drives.

So. Uninstalling and reinstalling the program did work. I'll never assume it won't work ever again. Thank you.

 

[Night Hawk]

Glad to hear that went well for you! It's always hard to say if a fresh install will be the solution in every circumstance however. Here it was simply using a totally different optical drive for the video editing program rather then a fresh install that saw working results while the first drives are still working well as always.

As far as the read and write times on each of the Sata II OS drive here I wouldn't be able to say I noticed any difference overall. The access times for the other pair of Sata III drives would remain the same anyways since Windows didn't see them reinstalled as SCSI devices.

While the changeover was simply automatic in 7 I wouldn't advise anyone to try this without first planning a clean install of the next Windows version to come however! The simple change didn't go so well for the Windows 8 Release Preview install on the second OS drive however. That would now need another clean install to see if 8 will run on it's own without a separate driver disk.

 

[DCMKC]

I followed the guide, but I got the dreaded bsod. I disabled all drives but my boot drive and the computer fired right up. Installed the drivers turned off the computer reattached all the hard drives, rebooted and everything is now fine.

 

[Night Hawk]

Glad to hear you were able to solve it that fast! DCMKC Welcome to SF by the way!

The problem I had when first getting this case together with a fresh install of 7 was the board was shipped with it set to AHCI. Apparently not already having Windows installed with all drivers and updates was why when switching to the Native ide setting 7 then loaded up normally.

With the recent clean install seen to all the board, chipset, sata and ide controllers drivers were already inplace to see 7 simply mount and install the two OS drives with a prompt to restart. It then added in the other pair of storage drives still left in ide mode however being Sata III not II models.

 

[ICIT2LOL]

Just done an install on a Toshy laptop and get to the mrxsmb / mrxsmb10 / mrxsmb20 and they open into "Enum"

Below those entries there is a folder / entry msahci that also opens to "Enum" but go back and I have a load of entries that include one that is titled
"ImagePath" that has "REG+EXPAND_SZ" then "system32\drivers\msahci.sys"

Now I am little confused as to which of the entries I should be looking at - I haven't looked in the BIOS yet for any refs to AHCI so perhaps this machine (2008) is too old to use AHCI?