My DVD reader is not working and I need to reload my system. So I want to use a .dmg file as described here (http://www.tech-recipes.com/rx/2628/install_os_x_from_dmg_file/). I found another site that says how to create a .cdr file from the DVD (http://www.kenstone.net/fcp_homepage/making_dvd_copies.html). The site implies that a .cdr file is a .dmg file. I can create the .dmg file using a friend's computer. But I'm not clear on how to load OSX from the .dmg. Am I on the right track?