Currently Being ModeratedApr 19, 2012 1:46 PM (in response to Coulter)
You mean the Snow Leopard installer disk, I presume. Have you opened a Finder window to confirm that it's not showing there either? It's possible that you just don't have the proper items set to appear on your Desktop in the Finder preferences.
If the disk doesn't appear in a Finder window either, then you may have a malfunctioning optical drive. Will any other DVD work? Can you get the system to boot to the disk if you restart the machine and hold down the "c" key?
Currently Being ModeratedApr 19, 2012 1:56 PM (in response to varjak paw)
Yes, I do mean the installer disk.
It does not show up in the Finder window either.
The CD drive works fine I can use a music CD or other CD's and it works'
I can't boot from the disk while holding down the "C" key ???
Any other ideas?
Currently Being ModeratedApr 19, 2012 2:05 PM (in response to Coulter)
CDs and DVDs are different and use different components in the drive, and one type may work in the drive while the other does not. So that a CD works really doesn't tell you much. Try a different DVD, if you can find one; the original 10.5 installer disk, if you still have it. If that doesn't work either, then you may well have a defective optical drive.
Currently Being ModeratedApr 20, 2012 7:12 AM (in response to Coulter)
It does sound likely that the drive has failed, yes. You'll need to contact an Apple Store or authorized service center and ask what it would cost to confirm the diagnosis and replace the drive. It's possible for a user to replace the drive oneself, but the iMac is not designed for user service and can be a bit tricky (more so for some models that for others). If you want to look into it, though, you can find guides for doing so here:
You could also look into an external drive. Some at least can be booted from, though I don't know if all can. Someone else here may be able to recommend a specific unit, or you can ask Other World Computing; they're pretty knowledgable about such things and I'd trust what they told me: