Its best if you avoid using common keywords when searching for Mac Os X 10.5 For Ibook G4. While early (10.0 and 10.1) versions of OS X are limited to software rendering only (thus, theyre sluggish on all supported Macs), 10.2 and later really, really want a G4 Mac with AGP graphics. Pop in the Mac OS X Install CD/DVD that your friend gave you with the computer, boot from the CD by holding down the c key as the computer starts up, and follow the on-screen prompts to do an 'Erase and Install.' H. or, you could restore from another Mac, or restoring from another hard drive is possible, too. Mac Os X 10.5 For Ibook G4 was added to DownloadKeeper this week and last updated on 0.New downloads are added to the member section daily and we now have 398,822 downloads for our members, including: TV, Movies, Software, Games, Music and More. What do you do if you want to have an operating system on your old Mac? You'll need an installer for that. The good method is to connect to another Mac, using a firewire cable, then boot this Mac in Target Drive mode (restart while holding the letter T, until you see the floating firewire icon) - then your Mac should appear on the desktop of your OTHER Mac, so run Disk Utility, and erase away, if that's what you want to do. If you are erasing the hard drive, then passing on to someone else - how are they going to use the Mac if there's no operating system installed? This workaround can also be applied to install Mac OS X 10.5 Leopard but the caveat is that it has to be done from a system that is certified to fulfil the minimum specs required to run Mac OS X 10.5 Leopard. Older OS X systems - I think you could, in theory, do that in Single-user mode. Once that is completed, simply plant the Mac OS X 10.4 Tiger installed hard drive into the PowerMac G4 and boot it up. If you are running Lion (OS X 10.7), you can boot to the Lion Recovery partition, run Disk Utility, and erase the hard drive.