Windows 10

Enable AHCI Without Reinstalling OS in Windows 10 and 7

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:

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:

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: 
  2. Find the key HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\iaStorAV\StartOverride and set 0 to 0: 
  3. Go to HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\storahci\ and  set Start to 0: 
  4. And finally find the last key HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\storahci\StartOverride\ and set 0 to 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: find SATA AHCI Mode and switch it to AHCI: Save UEFI (BIOS) settings and reboot your PC.

Enable AHCI Mode In Windows 7 Without Reinstalling

  1. Launch the registry editor: 
  2. Navigate to: 
    HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\msahci
  3. Set the Start value to 0:
Windows 7 msahci Start 0
  • Reboot your system.
  • Go to UEFI/BIOS during the reboot and change IDE to AHCI.
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    Adam Swift

    Adam is a real tech maniac. He likes to spend time testing phones, tablets, laptops, as well as any other technical devices, and write practical manuals on their functions. He often sleeps all day, but always works at night. Adam bought his first computer in 1999, being an absolute beginner who never held a computer mouse in his hands. He began to study Windows, constantly experimented and often crashed the operating system. But six months later, he was able to reinstall Windows 98 from a scratch on his own, fix almost any software problem on a PC, he also did hardware upgrades and realized that computers, operating systems and programs are now his biggest passion. In addition, Adam has always been a big lover of phones. With the advent of smartphones with Android OS, he began to pick at them much more than in computers. Now Adam loves to study privacy issues in instant messengers, blocking unwanted calls and other nuances related to privacy and security on the network. You can follow him on Twitter: https://twitter.com/tunecomp

    View Comments

    • 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

    Leave a Comment
    Published by
    Adam Swift
    2018-01-02 10:02

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