INSTALL MAC OS X LION

BEFORE INSTALLING MAC OS X LION

Your BIOS must be configured in-order to get the installer running. Press Esc when the machine boots up, and select Enter Setup in the menu that appears.

Under Advanced tab, select SATA Configuration. In that, make sure that SATA Mode Selection is set to AHCI. If not, then change it to AHCI. 

Under Security tab, select I/O Interface Security. Change the Audio Interface option to Lock. This is a work-around to prevent the Installer getting stuck before it completely loads.

INSTALLING MAC OS X LION

These items are required to create the Installer:

• USB Flash drive, size not less than 8GB
• A machine running at least Mac OS X Snow Leopard
• Install Mac OS X Lion.app purchased from Mac App Store

Follow tonymacx86's Unibeast method to set up the Installer on the flash drive and install it on to the system.

http://tonymacx86.blogspot.com/2011/10/unibeast-install-mac-os-x-lion-using.html