This section, method, or task contains steps that tell you how to modify the registry. However, serious problems might occur if you modify the registry incorrectly. Therefore, make sure that you follow these steps carefully. For added protection, back up the registry before you modify it. Then, you can restore the registry if a problem occurs.
To resolve this issue, enable the AHCI driver in the registry before you change the SATA mode of the boot drive. To do this, follow these steps:
- Exit all Windows-based programs.
- Click Start, type regedit in the Start Search box, and then press ENTER.
- If you receive the User Account Control dialog box, click Continue.
- Locate and then click the following registry subkey: HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\Msahci
- In the right pane, right-click Start in the Name column, and then click Modify.
- In the Value data box, type 0, and then click OK.
- On the File menu, click Exit to close Registry Editor.
For example, assume that you install Windows Vista or Windows 7 on a computer that contains a controller that uses the Pciide.sys driver. Later, you change the SATA mode to AHCI. Therefore, the drive must now load the Msahci.sys driver. However, you must enable the Msahci.sys driver before you make this change.
This issue affects only the boot drive. If the drive that you change is not the boot drive, you do not experience this issue.
AHCI provides several features for SATA devices. These include hot plug functionality and power management functionality. For more information about the AHCI specification, visit the following Intel Web site: