i really need help with this new disk utility, trying to make OS X 10.8 bootable disk by using disk utility. there is no option for burn in disk utility anymore but from the .dmg file if i burn its not making it bootable. really appreciate if an1 help
The usual sequence for converting the 10.8 download into a bootable installer: http://osxdaily.com/2012/02/17/make-bootable-os-x-10-8-mountain-lion-usb-install -drive/
If that's not what you're using to create the bootable installer, try it.
If that is the sequence that you're trying, try creating it on a different external device, and then maybe try downloading the installer from Apple again?
You can make a bootable USB stick to install using this free program which will do all the work for you.
disk utility
