How to enable the SATA hard drive AHCI mode after installing Win7

After Windows 7 is installed, When you enable the AHCI function of the SATA hard disk in the BIOS, the system will fail to start. The system will recover to normal only after you change to the IDE (ATA) mode. If Windows is installed in IDE mode, you need to reinstall the system to change the hard disk to AHCI mode in BIOS. This allows many users to reload data.
I. Introduction to AHCI

AHCI (Serial ATA Advanced Host Controller Interface) Serial ATA Advanced control Interface (Advanced Host Controller Interface) is an Interface standard jointly developed by multiple companies under the guidance of Intel, it allows storage drivers to enable advanced Serial ATA features, such as local command queues and hot swapping, its R & D team members mainly include Intel, AMD, Dell, Marvell, Alto, Microsoft, Red Hat, Seagate, StorageGear and other famous enterprises.

AHCI is essentially a PCI device, it acts as a common interface between the system memory bus and the internal logic of the Serial ATA device (that is, it is common in different operating systems and hardware ). This type of device describes a general system memory structure that includes control and status areas and command sequence entry tables. Each Command table entry contains SATA device programming information, and a pointer to the description table (used to transmit data on devices and hosts.

AHCI includes a pci bar (base address register) to implement native SATA functionality. Thanks to the successful development of the AHCI unified interface, the development of supporting Serial ATA products is greatly simplified, and the operating system and equipment manufacturer do not need to Develop interfaces separately, instead, you can perform operations directly on the unified interface to implement various functions, including NCQ (Native Command Queuing.

Ii. AHCI enabling Method

1. Click Start → run (or use Win + R) → type regedit → OK → start Registry Editor → expand to [HKEY_LOCAL_MACHINESYSTEMCurrentControlSetservicesmsahci] branch in sequence.

2. On the right side, double-click "Start" → "Edit DWORD Value" → change the key value of "value data" from "3" to "0" → click "OK ".

3. close the registry editor window and restart your computer.

4. when the system starts, press "F2" (depending on the computer's key) to go To the BIOS settings page and change the hard disk to "AHCI" mode. The general position is: "Devices" → "ATA Drives Setup" → "Configure SATA as" → "AHCI", save and exit BIOS.

5. After the system is restarted, it is successfully modified to the AHCI interface standard.

After the above introduction, I believe everyone has some knowledge about how to enable SATA hard drive AHCI for Windows 7 without reinstalling the registry. When you install the system without setting the AHCI interface standard, you can use this method to modify it without reinstalling the system.