Beware If Taking the AHCI Plunge

With a recent BIOS update, I noticed a new option for AHCI vs. IDE mode. Even though Vista has support for this new supposedly feature-rich disk technology, those drivers are disabled after installation. Vista won't even boot after making the change in BIOS to AHCI unless you first do the following:

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:

1.	Exit all Windows-based programs.
2.	Click Start, type regedit in the Start Search box, and then press ENTER.
3.	If you receive the User Account Control dialog box, click Continue.
4.	Locate and then click the following registry subkey: HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\Msahci
5.	In the right pane, right-click Start in the Name column, and then click Modify.
6.	In the Value data box, type 0, and then click OK.
7.	On the File menu, click Exit to close Registry Editor.

From KB 922976