09-27-2011, 11:19 PM

I have a Intel based MacBook Pro that recently had a hard drive go bad. I replaced the hard drive. My DVD Drive is also bad. I put an .ISO of Mac OS X On my external hard drive, hoping to boot from that to reinstall Mac OS. I plugged in the external hard drive, restarted the computer and held the "option" key as instructed by Apple's knowledge base. Instead of the folder with a question mark on it, I do get an arrow, but nothing else. Will it not boot because it's an ISO and wasn't "burned" to my external HD? Any help is much appreciated. None of my copies are illegal or counterfeit either, before I am asked.

09-27-2011, 11:52 PM

I'm having a similar issue, but at a different stage. HDD was bad and is now replaced, DVD Drive is defective, so I'm attempting to boot from external hard drive, GUID formatted with an MAC OS X iso. When I start the computer, I hold the option key and it gives me a black arrow, but nothing else. Can I not boot from an ISO? Please advise.

09-28-2011, 01:51 AM

OS X has to be installed on the external drive before it will boot.

And please do not cross post. Your other post was merged together here. Only post to one forum and continue posting back to the same thread.