Hello: I have an iMac with a single empty partition created by disk util. And I was going to upgrade to Lion but could not. Called Apple Care and was told to format my HDD and install original 10.4.3 Tiger then do the upgrade path. I received in the mail today the 4 CD set of 10.4.3 Tiger install disks. I insert Install Disk 1 and start the machine with C key held during the startup chime. And I get the gray screen with the flashing question mark folder. Some how I was thinking that it would boot and start the install program. Silly me. Any ideas on how to boot this imac and get the install start_edd? TIA, eddacker BTW I have verified that all my hardware is good and ready for Lion. When I bought this it had a new install of Leopard and a couple of months ago I upgraded to Snow. But Lion has proved somewhat problematic.