Hi- I've read many threads about this, but none that solve my problem. I'm trying to upgrade from 10.4.11 to 10.5.2. I have the discs to upgrade, yet when I try to install, I get an error message saying that it can't be installed on my computer - but with no explanation. This is what I've got: Model Name: MacBook Model Identifier: MacBook2,1 Processor Name: Intel Core 2 Duo Processor Speed: 2 GHz Number Of Processors: 1 Total Number Of Cores: 2 L2 Cache (per processor): 4 MB Memory: 1 GB Bus Speed: 667 MHz Boot ROM Version: MB21.00A5.B07 SMC Version: 1.13f3 I am NOT a techie, and am looking for detailed, step by step instructions for whatever I have to do to get this upgrade on my computer. I have an external hard drive to copy all my data to, so not worried about losing anything. Thank you!