# OSX Installation Fails Mysteriously



## robenghuse (Mar 3, 2011)

When trying to install my developer preview for 10.7 Lion, I receive the following message after about 99% of installation:

"An error occurred while preparing the installation. Try running this application again. If the problem persists, go to the computer with the Mac OS X Install DVD, open Remote Install Mac OS X (located in the Utilities folder in the Applications folder) and follow the onscreen instructions for restarting your computer using the DVD When the Mac OS X Installer opens, follow the onscreen instructions to install Mac OS X."

I already tried to reformat the entire harddrive and checked it with disk utility.

Anybody can help me?


Tanks a lot!


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## Giaguara (Mar 3, 2011)

Look at the installation console log during the installation and for any errors.
The NDA of the product prevents it from being discussed (too loudly or too openly) before it's available for the general public. So if the installer log doesn't provide a clue (post the installer log errors here if you like; the error codes should not provide anything that should switch the world to a parallel universe etc), and the general installation troubleshooting wouldn't help the installation succeed in the end, I'd recommend http://developer.apple.com/devforums/ this should be the place for ADC cases that don't require a TSI, and it's definitely a good place to check for any existing/known issues with the installer before considering a bugreport.
(You will need you ADC account to log in)


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## vshorrghar (Jul 12, 2011)

I wasted my half of the day in the same issue saying "an error occured while preparing the installation .Try running this application again"

but I found a way to solve this issue , it worked for me you should try this out.

1. open disk utility--> mount lion.dmg-->create two partitions one of 20 Gb where you will actually install Lion OS other 10 GB for temporary use.

 2. In disk utility use restore option source will be your Lion installation media in my case it was lion.dmg file,, destination will be 10 GB temp partition which we created above, now restore it , wait for 8-10 minutes.

3. Once this is restored in 10 GB temp partition, open temp partition and run installation from there instead of Lion.dmg what you were doing earlier.

4. It worked for me , while writing here second Lion installation is going on on 3 of My mac pro servers. 

5. If have doubt contact me at vshorrghar@gmail.com

Purpose is to help Mac power users


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## Giaguara (Jul 12, 2011)

vshorrgar, thank you for your update. My post earlier was made in March - when any Lion installation errors were waaay more paranoidly controlled, and had to be behind closed doors and whatnot. But now that Lion is soon out and ready to roar (rawr!!) having an update for this isn't a bad thing. (Hopefully the issue will be resolved with the GM but you never know) 
Welcome to Macosx.com


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