AHCI Tweak in Win7 registry

Hi all, I have 2 questions please. I will be installing a current new Motherboard. My old one does not have the AHCI option. I will be taking my old hardrives along to the new board. Win 7 home is installed on drive C:. I gather that before I do a Sysprep that I need to do the registry tweak as in here :http://www.sevenforums.com/tutorials/61869-ahci-enable-windows-7-vista.html?ltr=A. Second...