Mountain Lion install failed and now can't access HD

I had this exact same problem on my 2008 Aluminum Macbook. I've been having problems with the drive and just assumed it was my drive, so I stuck in a new one from an external drive that I had sitting around. If you figure out the problem I would be interested.

See more threads and comments on internet, definitely mountain lion problem, apple should fix this real quickly, all restore tips won't work. Big bug.

Same here in my Mini. It's an Apple problem/bug. None of the recovery procedures will work. At this point all I can do is wait on Apple to fix the install and try again.

I am able to mount my Lion HD using the USB adapter that I had leftover from the the external drive. Everytime I do this, I get an error from ML that says that the harddrive has an error and I can only remove files from it, which I have been doing with little to no problems.

I can Cmd-R and verify and all is well. I run a fresh install and the exact issue. I have followed all procedures that have been presented and nothing works. I see dozens of comments that are describing my exact problem. This is an APPLE problem and I hope someone is woking on a fix in the install. I am out of work until my Mini gets fixed. Right now it is completely powered down because all it does is panic and restart....

I'm having the exact same issue and I am freaking out. I don't want to lose my files.

In order to do this you'll need an unused external drive that you don't mind taking apart (very simple to do). If you are able to get the drive apart (make sure it's a laptop sized drive) you should be able to swap the drives and install ML on the newly liberated drive. To do this you'll need to put the new drive inside your computer and connect the old drive to the remaining hard drive USB interface. When you try to finish the install just set the destination to the internal drive and it should work fine. It did for me.

Apple has severe bugs in the release. I am certain they are working a fix because MANY of us are dead in the water until soemthing is done.

Whatever you do, DO NOT REFORMAT THE DRIVE. You can just get a small <500Gb EXTERNAL bus powered drive, dismantle it and follow the instructions above. If you already have one then that's even better.

The drive I'm showing here is the drive that used to be inside of my computer. It took apart an old 320Gb seagate drive. The connections on these drives are all universally interchangeable. They just add some circuits and a USB (or other) interface. I would just get the cheapest drive that you can get that is for laptops and looks simple to take apart. (This is almost exactly the drive that I did this too http://www.amazon.com/Seagate-FreeAgent-Portable-External-ST903203FAA2E1-RK/dp/B 001FWIE0K/ref=sr_1_56?ie=UTF8&qid=1343340447&sr=8-56&keywords=seagate+external+h ard+drive)

The "old internal" drive should still be able to allow you to install ML on the "new" drive as long as you tell it to. It sounds complicated, but it's really not once you get in there and start doing it. It was actually quite easy.