Hi Mikey, I found Leopard to be problematic on that G4 or any G4 for that matter. So consider opting for an earlier OS. Applejack is an excellent troubleshooting freebie. However you need to run it in Single User Mode. Go to the Mac Apple site and read up on what that is if you don't already know. Below is a link to the Applejack download site. http://sourceforge.net/projects/applejack/ Read the reviews on this download page. I haven't used it in several years as I currently use Alsoft's Disk Warrior. So there are limits to the help I can offer you, but I learned how to use Applejack cold and I did it slowly step-by-step and I recall that it saved my butt at that time. Disk Warrior costs about $120 but the interface and the support from Alsoft when you are in a jam is first rate. However Applejack should help you clean up what ails your Mac. It is an excellent maintenance tool and it is free. Good luck, Bill