PIPPOX0, I too have an Optiplex 760 (2nd from the smallest), and have been 90% successful in trying to get ML installed on it. I am completely stumped as to where you can set the AHCI settings in BIOS on the 760. I also have a 755 which the BIOS is completely different (760 has a gui, 755 doesn't). I have tried using the myHack EDP setup located at http://osxlatitude.com and am able to get ML installed, up and running, but cannot seem to get any of the kext to work without hosing the boot. Might I simply ask you where you set the AHCI in BIOS? I just cannot find it.