"Cannot be installed on this computer" -- no error message

[GhengisPrime]

I just bought an older iMac off eBay (and it wasn't a box of bricks! yay!) for my daughter. Since it came with Leopard and I have a Snow Leopard install disc lying around, I thought I'd bring it up to the current OS version.

When I put in the disc, I tried booting with "C" held, but the Apple logo changed to a "no" sign (grey circle with a line through it), and the system booted straight to the desktop as usual.

After the normal boot process completed, the install DVD opened and I double-clicked "Install OSX". The "Install OSX" dialog appeared for a moment, then a text box appeared over top of the prompt that said "Mac OSX Snow Leopard cannot be installed on this computer." All I could do was quit.

I opened the Install Log (Command-L), and it says this:

Apr 21 21:16:57 blanca Install Mac OS X[121]: @(#)PROGRAM:Install  PROJECT:Install-388
Apr 21 21:16:57 blanca Install Mac OS X[121]: @(#)PROGRAM:Install Mac OS X  PROJECT:InstallAssistant-49
Apr 21 21:16:57 blanca Install Mac OS X[121]: Hardware: iMac5,1 @ 2.16 GHz (x 2), 1536 MB RAM
Apr 21 21:16:57 blanca Install Mac OS X[121]: Running OS Build: Mac OS X 10.5.8 (9L31a)
Apr 21 21:16:57 blanca Install Mac OS X[121]: Env: PATH=/usr/bin:/bin:/usr/sbin:/sbin
Apr 21 21:16:57 blanca Install Mac OS X[121]: Env: TMPDIR=/var/folders/nQ/nQeS6ETBGv8Lx2ZVB0cgoU+++TI/-Tmp-/
Apr 21 21:16:57 blanca Install Mac OS X[121]: Env: SHELL=/bin/bash
Apr 21 21:16:57 blanca Install Mac OS X[121]: Env: DISPLAY=/tmp/launch-i790jb/:0
Apr 21 21:16:57 blanca Install Mac OS X[121]: Env: SSH_AUTH_SOCK=/tmp/launch-9xhG46/Listeners
Apr 21 21:16:57 blanca Install Mac OS X[121]: Env: Apple_PubSub_Socket_Render=/tmp/launch-XZKird/Render
Apr 21 21:16:57 blanca Install Mac OS X[121]: Env: __CF_USER_TEXT_ENCODING=0x1F5:0:0
Apr 21 21:16:57 blanca Install Mac OS X[121]: Env: SECURITYSESSIONID=ab3190
Apr 21 21:16:57 blanca Install Mac OS X[121]: Env: COMMAND_MODE=unix2003
Apr 21 21:16:57 blanca Install Mac OS X[121]: Env: Install_Mac_OS_XVersionString=@(#)PROGRAM:Install Mac OS X  PROJECT:InstallAssistant-49
Apr 21 21:16:57 blanca Install Mac OS X[121]: Using install media product at /Volumes/Mac OS X Install DVD/System/Installation/Packages
Apr 21 21:16:57 blanca Install Mac OS X[121]: Will bless Mac OS X Install DVD (disk1s3)
Apr 21 21:16:58 blanca Install Mac OS X[121]: Failed installation-check  {\n    NSLocalizedDescription = "";\n    NSLocalizedFailureReason = " ";\n}

I'm at a loss -- as you can see, the "FailureReason" is an empty string. I rebooted holding Alt (it's a PC keyboard...), chose the install DVD, and after a while, it came up to a very similar screen with a similarly-worded popup (this time in a modal dialog rather than a simple text box), with the only options being "restore from time machine backup" or "reboot".

Is there something strange with my install disc? Is this computer (identifies itself as "iMac5,1"; I think it's this) incapable of running SL? AFAIK I've seen people post elsewhere that they have this exact model and they identify their OS as SL, so I don't think that's it. The install disc says "Mac OS version 10.6.2 / Disc version 1.0", then has what looks like a part number, if that makes a difference.

 

[natewsmith]

Yeah there is something wrong with your install disc.

I had the the same problem and it took me for EVER to figure it out. And it was a replacement disc from APPLE no less.

All I ever got was the same message you got.

You need to first use the original discs that came with the Computer.

Mac OS Version 10.4.7/AHT version 3A112/Disc version 1.0/2Z691-5883-A There are 2 discs - the first is labeled iMac MAC OS X Install Disc 1 and the second is iMac MAC OS X Install Disc 2.

 

[GhengisPrime]

You need to first use the original discs that came with the Computer.

Mac OS Version 10.4.7/AHT version 3A112/Disc version 1.0/2Z691-5883-A There are 2 discs - the first is labeled iMac MAC OS X Install Disc 1 and the second is iMac MAC OS X Install Disc 2.

Uh-oh. As I said in the OP, this was an eBay buy -- shipped with the core computer only (hence the PC keyboard). It shipped with a fresh install of 10.5.something, now running 10.5.8 (maybe after a software update? my wife did some of the setup).

Do I need to borrow some old install discs, roll back to 10.4.7, then try to update using the SL install disc I have now? Should I contact Apple and request a replacement SL disc? Is there any way I can "test" the SL disc I have to see if it is in fact hosed?

 

[robbieduncan]

Unless you have a retail-purchased Family Pack of Snow Leopard you are committing copyright infringement: you have a license for one (1) install only.

Also unless your SL DVD is a retail copy (i.e. not shipped with a new Mac) this won't work: restore DVDs are locked to only work on the hardware they ship with to prevent this sort of casual piracy.