Install Disk for Snow Leopard will not boot on an iMac 27in

Same issue on a imac 27" (late 2009/early 2010). Cannot boot from firewire drives with earlier version of OS, and cannot boot from SL disk...

Same problem here. When power is turned on log a appears starts to load two times unsuccessfully and turn off. Tried to boot in windows gets me a bit further, to the startup screen of windows but than also turns off. Tried to boot from original install disk, disk makes a bit of noise than the grey screen with logo appears and freezes but does not turn off. Reset Pram with keys and power cord cutoff to no avail. Tried apple hardware test but that freezes just before the end of the test, so I do not know whether it is a hardware failure. would be nice to get a reaction form an apple support guy as apparently more people have this issue.

Hi guys

You need to boot from the disks that came with your Mac, SL was released before the 27" iMacs so it cant boot them. Lion will be the first retail copy of OS X that will boot these macs. the copy of SL that came with your mac is 10.6.4 or something but the retail copy of SL is 10.0.0 it doesn't have the drivers for your mac to boot.

Not quite accurate; the current retail DVD is 10.6.3. Result is still the same; you can't boot any Mac from an OS version earlier than that with which it shipped.

So DON'T lose the OE discs! (I keep mine in the safe).

I've maintained a bootable external Snow Leopard drive as a precaution in the past. However, with Lion installed, selecting that drive on startup (option key) causes a kernel panic. The actual result is that the selection screen remains while command line text goes across the screen until the dreaded kernel panic wipe.

I thought I'd go ahead and create a new drive by using my retail box copy of Snow Leopard. Attempting to boot from cd (C key on startup) causes the same/similar kernel panic.

Then I thought I would try to run the SL installer from Lion, hoping it would allow me to select the external drive as the destination. No dice as the installer won't start, giving the message that it cannot be run.

Sadly, this is all a side project so I can run the stupid Intuit converter to recover Quicken 2007 files for Quicken Essentials to use. Apparently, one must know intuitively that you have to do that before you upgrade to Lion, becaues the fine folks at Intuit can't figure out how to read the old qdfm file...but that's another thread!

I have a brand new 27" iMac that came with Lion preinstalled. It kernel panics when I try to boot from the Snow Leopard retail DVD. lol, impossible to downgrade to Snow Leopard.

If it shipped with Lion, SL isn't possible.

Yes, it is ridiculous how it is impossible to install Snow Leopard. I have two Snow Leopard DVDs: one that I purchased for a Macbook soon after it's release (10.6.0), and one that came with my iMac (10.6.4). Both of these boot up my Macbook (running 10.6.7) just fine. My SL 10.6.0 DVD mounts onto my iMac (Lion 10.7.0), but you cannot run the install. I attempted to boot from this DVD and got the infinite white screen and Apple logo, as some have reported above. The other SL 10.6.4 DVD will not even mount in Lion, and will not even show up as a bootable drive when I attempt to select it after holding alt/option on reboot.

I created a bootable external drive from SL 10.6.0, attempted boot, same infinite white screen/apple logo.

I created a bootable external drive from SL 10.6.4 on my macbook. I attempted to boot from this drive, and got the white screen of death, except that this time I actually got the loading symbol underneath the Apple logo. After about a minute of attempting to boot, the Apple logo changed to a circle with a diagonal line through it (the "NO!" sign).

I took my iMac to the genius bar. They inserted SL 10.6.0, which would not boot. Then they determined that my computer had to run 10.6.4 and later. So, they restored an image of SL 10.6.4 onto my partition (not an install from an image, but an image of SL already installed). Hurray! Snow Leopard was successfully shoved onto my iMac!

I then deleted a third partition on my hard drive I did not need anymore, which somehow screwed up my SL partition (even though it said "Will not erase partition SL or Macintosh HD). Now I am back at square one, and I guess I need to take my flippin iMac back to Apple for them to do what I should be able to do.

I like Apple, but sheesh do I hate Lion right now.

@peterfrommilton I realize now you meant "actually impossible." For me, it is practically impossible,...though seeming to be actually impossible right now.

That your iMac grey disc will boot the MB is a minor miracle. I doubt you could install from it though. And if you did, you may well find the MB will no longer charge or run from the battery; iMacs don't need the management software.

Now that you mention that, I'm not sure that I did actually BOOT my iMac from that particularly DVD. I did for sure on the 10.6.0 SL. It does mount, though, for sure. In any case, thanks for the uh....help??

*Macbook (not iMac).