Mac broke while trying to install Mountain Lion

It's being a pain in the arse huh?

Well zap the SMC and the PRAM, I suspect there is something there from the 10.8 installer that's trying to do it's thing.

#1 and #2 here

Step by Step to fix your Mac

Next try option key booting from the 10.7 Recovery USB again,

http://osxdaily.com/2011/08/08/lion-recovery-disk-assistant-tool-makes-external- lion-boot-recovery-drives/

use Disk Utility to Erase the hard drive with the middle option (one step from the right option) on the entire drive (select the drive makers name and size) on the left, it will take a bit, map off bad sectors and give you a brand new EFI and GUID partition map whichh also likely have been borked by 10.8 update.

Then install 10.7 via the USB, then commnad r boot and AppleID and password (required) for 10.7 install, then try updating to 10.8 again, I think it will go well this time.

If not, if you have a Firewire cable and another Mac, you can T boot the sick Mac's hard drive to the desktop of the other and use Disk Utlility to wipe the drive that way.

Another method is to use another Mac to burn a ISO of Parted Magic to cd and option or c boot the problem Mac with that, use the default load in RAM option and it will spit out the disk, use the mount disk option and erase the disk with extreme prejudice. LOL. 😉

i had the exact same problem this morning and i just got back from the genius bar. he told me that the OS does a check on your system before it installs and that check found enough problems on the drive to abort the instalation. the only option he gave me was a new drive, either in-store or on my own. at no point did they offer to fix it for me.

on one hand, im happy the problem has a solution. on the other hand i am livid that i paid $20 for an "upgrade" that destroyed my drive, which was working properly before the update, regardless of what the tech thinks.

yah man i feel you, my last back up was about 3 months ago 😟
however i did just discover that my windows bootcamp partition is 100% fine and i can access all my personal files on my mac partition through windows (never thought id be so happy to see the windows logo haha)
this also leads me to believe that my drive is fine and there is something else going on here.

vrot wrote:

Maybe it's some kind of bootable flag that was turned off?

You can use a PC or a Mac to burn a ISO of Parted Magic to a cd and boot the Mac off of that and go hog wild in turning off the boot flags and erasing the disk, you just need the hardware at this point so anything done to the drive is optional, you want it messed up good so it won't work at all on a Mac so you can reformat it again.

Another option is remove the hard drive out of the machine and use a SATA to USB adapter cable to erase (not quick erase/format) the disk on a PC. (right click and format anything just to wipe the thing clean.

http://eshop.macsales.com/installvideos/

However when you format with the Lion USB once the drive is back into the machine, you need to use the middle erase option (it's to the right a bit) the entire drive to map off the bad sectors giving you the problem.

Reducing bad sectors effect on hard drives

There is no need for a new drive if you have just a few problematic bad sectors or a EFI firmware lock issue, your going to replace all the data on the drive anyway, you just need it erased.

There is no way to go back to 10.7 on that drive, once EFI and GUID partition table has been updated only a total drive erase and install of 10.7 can work, much like going back to 10.6 from 10.7 was.

Of course if your going to remove the drive, you may opt to increase it's performance or size with a better one or a SSD even.

I was having similar problems and tried a few things without success. As a last resort, I was about to ease my drive when undecided to UNMOUNT my BOOTCAMP partition. Once I did that, the DISK REPAIR worked and I was able to install from there.

Sounds good.

I forgot that Spotlight likes to index behind the scenes, which makes DU unable to unmount volumes because it's in use.

However you got to use Parted Magic, which is a wonderful tool

I had the exact same problem when upgrading my 2009 MacBook Pro (13", 4GB RAM, 320GB HDD, 2.26 C2D) to Mountain Lion (ML). I'm not as tech savvy, so I ended up going to the Genius Bar. They, too, had trouble upgrading me from Lion to ML. They ended up downgrading my computer to Snow Leopard before performing a direct upgrade to ML from there. Now, ML works without a hitch. The genius told me that Lion was especially buggy and that "ML is everything Lion should have been". Very interesting...

Hi, I'm having the exact same problem. How do you use Parted Magic? It seems like this is the only thing for me to try.