I've seen something about com.apple.boot.plist, but I need a little more further information. After type: Code: ioreg -p IODeviceTree -w0 -l | grep firmware-abi I receive the following from terminal: Code: | | "firmware-abi" = <"EFI64"> Looks that I am able to run 64 bit kernel. My computer is a white macbook early 2008. Core 2 Duo T8300 2.4GHz. If anyone can make a small guide, please!