i have an ASUS M5A88-M motherboard, and a Western Digital WD2503ABYX HDD. i am trying to make that drive work in AHCI mode, but when I try, the disk won't boot. i think the HDD is AHCI compatble, tho not certain. i went into the registry to set a value=o for the relevant AHCI parameter, but no luck. if i need a full re-installation of W7 64-bit, does it prompt me along the way to set the mode to IDE or AHCI? thanks.