Help "Switch to AHCI"

HI

I upgrade my pc's motherboard from Gigabyte EP41 to GA-H87 -HD3. But I can't run on it my hdd that windows xp installed on it before. I changed the AHCI mode to IDE in BIOS to try Install the AHCI driver by edit the registry as

http://forums.pcper.com/showthread.php?444831-HOWTO-enable-AHCI-mode-after-installing-Windows

but in the registry I can't find some item like "msahci" and in the otherwise you see iaStorA.sys and iaStorF.sys in the Gigabyte's site Driver.

I have some program that work only on xp.

with best regards.