I am the proud? owner of a PPC 1.8 17" iMac. It has 1.5 gig of ram and a 250 gig HDD.The previous owners' handling of the machine was appalling! It was dirty, case scuffed as well as the screen. It had no OS so I installed 10.4 and all was well. It upgraded to 10.4.11 without a hitch. But now I have tried to upgrade to 10.5 and ALL efforts have failed. I don't have an external firewire drive, another Mac computer, and have tried a memory stick with no positive results. The ONLY thing I have not tried has been a 100% original disk. I cannot afford the 1-200 dollars people are asking on ebay. And anyone with a disk locally will not lease, loan, SELL or otherwise part with the disk. Yet all say how easy it is to do. And OF COURSE all want to purchase it for $100.00 so so to ease my frustration. At this point, I'm considering a "hackentosh" with the use of the iMac's Hdd. My Mac does not recognize the startup disk OR thumb drive at startup or in the system preferences. Holding down buttons will not help either. The excitement of owning a Mac has been overshadowed by this issue. Have I missed something simple?