What is AHCI?
The acronym stands for Advanced Host Controller Interface. It refers to an updated command set used by the SATA channel on your motherboard or controller which can take advantage of some of the newer features of modern large hard drives and SSD’s. Most people have never heard of it until they started looking into how to optimize their system for their new super speed SSD (solid state hard drive).
When I enable AHCI in BIOS I get a Blue Screen of Death (B.S.O.D)
That’s actually to be expected. If your BIOS was set to IDE mode when you installed Windows originally then it didn’t detect the ACHI controller present and therefore didn’t bother to configure the registry to use ACHI. This confuses the system when the hard drive/SSD and Windows are actually speaking two different languages and don’t understand each other.Fortunately it’s a quick fix to get Windows to work with AHCI.
How to Enable AHCI in Your Windows Registry
Assuming that you’re using Windows 7 the process is as follows:1. Run regedit.exe (you can simply type it into the search box on your start menu)
2. Open HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlset\Services\msahci
3. Right Click on the object called “Start” and select “Modify…”
4. In the box labeled “Value Data:” enter the number 0 and click “ok”
5. exit Regedit
6. Reboot and enable AHCI in BIOS
2. Open HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlset\Services\msahci
3. Right Click on the object called “Start” and select “Modify…”
4. In the box labeled “Value Data:” enter the number 0 and click “ok”
5. exit Regedit
6. Reboot and enable AHCI in BIOS
For Windows 8 and Windows 10 the process is the same however the registry key is found at:HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlset\Services\storahci
