try doing this,
Create a bootable USB drive for your operating system doing this:
if that does not work and you have access to another mac running lion or later, do this:
Either way, once you have the recovery USB drive insert it into the computer, boot, and hold down option immediately after, and choose to boot from the USB drive as opposed to the main drive. Then erase and repartition your main drive and continue with the installation.
best of luck to you.
I am attempting to reinstall Mountain Lion. My MacBook Pro would not bootup last night, I received a grey screen and then it would just shutdown.
1. I tried removing the battery and keeping it plugged in, and the machine did the same thing.
2. I am unable to boot in Safe Mode (Holding left Shift key)
3. I tried resetting PRAM, still receive the same issue
I am able to access OS X Utilities Command+R and also boot up to the recovery partition by hold the Option/Alt key.
It cannot repair the disk
When repairing the disk I was instructed to reformat and reinstall the OS. That is fine, I have everything back up on a separate drive.
"An error occurred while preparing the installation. Try running this application again."
Erased disk. Verified the disk and said that it was ok. Attempted to re-Install, still gave same message
Ok, do this
1: Your going to need another 10.8 Mac with admin access to copy their Recovery HD to USB.
2: Select Disk Utility and select your hard drive on the left side top
3: Click Erase and use the middle selection (very important), Erase and wait, it will take some time.
4: Check the Partition, that the option is GUID and format is OS X extended journaled. Change this to MBR and MSDOS and Apply, then change it back to GUID and OS X extended journaled and apply.
We want to double make sure you get a new GUID partition table.
5: Quit and reinstall 10.8 from Apple's servers with your AppleID and password.
6: Reboot and setup with your same name as before, install programs from fresh sources and files from backup manually.
I don't advise TimeMachine restores after going through all this, pick files indivudually to restore.
What your basically doing is the ultimate install, blanking a entire drive like it was new from the factory and starting over.
The middle secure erase feature doubles as a method to check for bad sectors on the hard drive and maps them off before OS X or critical files laid.
If your hard drive still has problems after this, then it needs to be replaced.
2008 machine is too old to be running 10.8 in my opinion, it's almost 5 years old and on it's last legs.
10.6.8 should have been as far as it went.
Found the problem. When I looked at the install log it said that it couldn't verify the app.
Turned out to be a firewall problem at my work. Took it home, connected to the wireless and it installed just fine. I figured the download service would just use port 80, but it was doing something different.
So, I'm up and running again. Thanks for the responses.
Just want to let every know that I was having this problem and nothing seemed to work. Then I found this video http://www.youtube.com/watch?v=Cf4TzZt24-M that says you just need to reset the time using terminal in a few easy steps... and it worked