Hi all New to the forum. I need help to create a dual boot setup on my MBP 2.4 GHz Intel Core i7 that came with Mavericks 10.9.3 already installed. I need for some reasons (drivers of an audio interface that are not updated anymore) to have 10.7 Lion installed on a separate partition I created on the main drive. I tried to do this by creating a bootable USB pendrive and use the restore function to expand the InstallESD.dmg file from the original installation file downloaded from the Mac App Store. The creation of the USB drive seems to work, but when I reboot the Mac with ALT to show the bootable drives and choose the USB drive all I get is a grey screen with a "no parking" sign on it...and then after a few second the mac shuts off... Is there some kind of limitation imposed by Apple about this? Is there a way to create this dual boot setup or I'm desperately out of luck? Thanx L.G.