Snow Leopard Installation couldn't be completed.

Hello Community,

I just recently decided to upgrade my IMac OS running 10.5.8 to Snow Leopard. There were a few considerations that motivated this upgrade, mainly the need to run a 64bit version of Windows 7 through Bootcamp in the secondary partition in order to take advantage of the just upgraded 4GB of RAM.

So I went to the Apple Store on saturday morning, bought a DVD with SNL and set out to have a smooth update session.

I wasn't intending to do a fresh install even if I have all my data backed up through TimeMachine; so I followed the screen instructions from Leopard hoping for a quick upgrade, unfortunately after a restart and a grey screen lapse a message showed saying that the install couldn't be completed.

I carried out a few tests to determine the source of the failure as the scripted log was unreadable in plain english and didn't seem to throw any clues to the cause of the error.

I did a disk verification through DiskUtility which didn't find any errors on my HD; I also thought it could be related to the recently installed RAM so I carried out an extensive Apple Hardware Test using the original installation disk which took nearly 90 minutes and that also didn't show any errors.

At this point I thought I would try a fresh install by rebooting from the DVD but that operation was also unsuccessful.

I have read a few threads which point either to a faulty DVD (unlikely as I bought it brand new) or a problem with my optical drive.

Has anybody experienced something similar? I am on an Intel IMac Mid 2007 with Leopard 10.5.8.

Welcome to the Mac Forums.

It does sound like there may be a problem with the optical drive. Since the machine is a 2007 model the optical drive lens may be dirty or possibly defective. Try cleaning the lens. Use a can of compressed air and blow several blasts of air into the drive. That may or may not help but worth a try.

As far as the DVD being defective, you can always try to read it on another Mac if available. Or take it back to the store where you purchased it and have them test it for you.

Another thing you can try if you have a good Time Machine backup on hand is to erase the hard drive and install Snow Leopard clean. If it installs OK that way, do a complete restore of everything during the installation process. (It will ask.)

Thanks chscag,
I replaced the optical drive 18 months ago (still within the 3 year apple care thershold) after a disc got stucked; its been functioning fine so I am sceptical about it being faulty. Anyway, last night after trying a few other things (old RAM installed, rebooting from the DVD, making a new image and attempting the install from a memory stick) I decided to book an appointment with at the genius bar, I have it for tomorrow evening where I will be taking my IMac, the installation disk and the SNL upgrade disc. I will let you know what the outcome is. Thanks for your help.

An iMac that old should only be capable of Windows 7 32 bit version.

I am having the same issue but trying to boot from an USB drive. My optical drive currently does not work so I made a bootable USB drive.
Chscag, a friend of mine had an unused macbook laying around and gave it to me, I swapped the displays and that worked with my screen. You gave me advice on another thread about my display being dim.