Problems installing OSX from bootable USB drive
I'm trying to downgrade from 10.8.3 to 10.7.5, mainly because of the reduced battery life in Mountain Lion.
I have created a bootbale USB thumbdrive with 10.7.5 on it.
I restart the machine holding down the Option key, but the USB drive does not appear in the available drives. All that appears is the Macintosh HD and the 10.8.3 recovery.
Why is the USB not appearing.
I have a retina MacBook Pro 15 from mid 2012. It was shipped with Lion.
Nigel
MacBook Pro with Retina display, OS X Mountain Lion (10.8.3)