12-11-2012, 06:06 AM
If holding the option key does not bring up any bootable drives then the method you used to create the bootable usb failed. I never had any luck with Lion Diskmaker , Ive always just used disk utility to create the bootable image .
You need to do this from a running OSX
Insert the usb drive , it will need to be an 8gig or more.
open disk utility and let it find your usb drive..
In the left hand pane select your usb drive ..
then in the right hand pane select the partition tab.
In the drop down menu select Mac OS Extended Journaled
In the top drop down menu selct 1
then in the options menu make sure you select guid to use a bootable drive on mac
once it is partitioned select restore.
Now drag or select your mountain lion Image into the source box
Drag your new partition into the destination box
click restore and let it go.