How can I enable AHCI on a SATA drive after installing Windows?

You need to make the msahci and/or IastorV drivers be loaded early.

(Note: For Windows 10, the built-in driver is called storahci.)

According to Microsoft KB 922976, run Fix it 50470 or open regedit, navigate to one of these keys:

and set the value of the Start dword to 0.

using regedit to enable AHCI mode in Windows 7

Reboot and enable AHCI in BIOS, now it should work.

Remember to create a restore point before any changes, just in case.

The same registry changes can be done via Cmd, using reg add or sc config:

Check current parameters (and make sure the service exists):
```
sc qc msahci
```
Change the boot mode:
```
sc config msahci start= boot
```
(Note that start= is a single parameter, but boot is separate.)

CGA

Posted 2010-02-19T16:58:50.787

Reputation: 3 767

1It only worked when I followed your procedure. – Jader Dias – 2010-02-20T02:36:19.280

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