I’ve been upgrading quite a few machines from Windows XP to Windows 7 lately, and for some reason, almost every time, I forget to change the SATA Operation setting in the BIOS from ATA to AHCI after wiping the drive and before installing Windows 7.
AHCI (Advanced Host Controller Interface) is a new interface specification that allows the SATA controller driver to support advanced features that can give better performance out of SATA hard drives, especially in Windows Vista/7.
After two or three times of restarting the Windows 7 installation process after changing the SATA Operation to AHCI in the BIOS, I thought their must be a way to make this change without having to reinstall Windows. After a little digging, I found out their is a simple registry change that can be made that will allow for the SATA Operation change. Here’s what you can do:
- Start “regedit.exe”
- Browse to HKLM\System\CurrentControlSet\Services\msahci\
- Change the DWord value named “Start” from “3” (ATA) to “0” (AHCI)
- Shutdown the computer
- Power the computer back on, making sure to enter the BIOS and change the SATA Operation to AHCI
- Save the change
Warning: Changes made to the Windows registry happen immediately, and no backup is automatically made. Do not edit the Windows registry unless you are confident about doing so. Creating a backup before editing the registry is highly recommended.