Enable AHCI Without Reinstalling OS in Windows 10 and 7

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SATA AHCI Mode Enable

AHCI (Advanced Host Controller Interface) mode is a communication mode that serves to connect storage devices using SATA interface with the support of NCQ and hot plug features.

On practice this mode often provides faster read/write speeds while using HDDs and especially SSDs.

Quite often users find that they have AHCI disabled and try to enable the mode in UEFI (BIOS) but get the BlueScreen issue with the code Inaccessible_boot_device.

Below we will explain how to check if AHCI mode is enabled and how to safely enable it without reinstalling Windows 10 or 7 and avoid BSOD.

Why You Need to Have AHCI Enabled For SSD

Don’t think that AHCI mode is useless for you. I know why you think it is – because someday you tried to enable it when you were using a classic HDD (Hard Disk Drive) and AHCI did not boost the speed.

But it works for SSD!

Even if you have an old SATA 2 controller you will feel the difference in read and write speeds when you enable AHCI mode. Look at the SSD performance comparison on my old HP G62 from 2011:

AHCI mode on SATA2
SSD speed with AHCI vs IDE on SATA2 controller

How To Check Whether AHCI Is Enabled Or Disabled

  1. Open the Device Manager.
  2. Expand the IDE ATA / ATAPI Controllers.

If you see AHCI Controller in the list, you have it enabled:

SATA Controller AHCI Mode

If you see only ATA and IDE words you are likely to have AHCI feature disabled on your machine!

How to Enable AHCI On Windows 10 After Installing

If you have already installed and set up your Windows 10 with your SATA controller running IDE compatible mode don’t be upset! You can switch to AHCI in a few steps.

To be on the safe side, it is advised to back up your Windows 10 using AOMEI backupper before you start tweaking the registry.

Launch the registry editor (Win+R, type regedit, press Enter) and perform the following actions:

  1. Go to HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\iaStorV and set the value named Start to 0: iaStorV start 0
  2. Find the key HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\iaStorAV\StartOverride and set 0 to 0: iaStorV StartOverride 0 0
  3. Go to HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\storahci\ and  set Start to 0: storahci Start 0
  4. And finally find the last key HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\storahci\StartOverride\ and set 0 to 0: storahci StartOverride 0 0
  5. Reboot your system.
  6. Go to UEFI/BIOS and enable AHCI mode.
    Here is how it looks on an old desktop with AWARD BIOS. You need to go to Integrated Peripherals: Award BIOS Integrated Peripheralsfind SATA AHCI Mode and switch it to AHCI: SATA AHCI Mode EnableSave UEFI (BIOS) settings and reboot your PC.

Enable AHCI Mode In Windows 7 Without Reinstalling

  1. Launch the registry editor: regedit-win7
  2. Navigate to: 
    HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\msahci
  3. Set the Start value to 0:
enable AHCI mode without reinstalling Windows
Windows 7 msahci Start 0
  • Reboot your system.
  • Go to UEFI/BIOS during the reboot and change IDE to AHCI.
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    1 thought on “Enable AHCI Without Reinstalling OS in Windows 10 and 7”

    1. Hello,
      Thanks for your article.
      On my old ASUS K70iC, I didn’t see the “Standard SATA AHCI Controller” in Device Manager.
      So I went into the registry. But I only see iaStorV and iaStorAVC, no iaStorAV.
      What can I do in this case?
      Thanks in advance for your help !
      Pierre

      Reply

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