I have a PowerPC Powerbook G4 running OS10.5.8 which has been running very roughly recently. I'm going on a trip at the end of next week and decided to check it out today. I found that the problem is a disc one: running Disk Utility, I'm told that there is a directory count mismatch, and Disk Utility can't repair it. It's an old machine and I can't find the operating system installation disc, so I can't reinstall from scratch, and I'd like to avoid this because the last backup was some months ago and anyway it's time-consuming. Various websites advised DiskWarrior, which I duly bought online for about $120. The instructions were a bit confusing and I started by trying to run DiskWarrior from the hard disc, but generated the message that you could not run it on the disc it was repairing. I tried to run DiskWarrior from a DVD, but got the message that "OSX ignores ownership of some disks by default" and that I should either run it from the application installation disk, or change the permissions on the disk by accessing the Info item on the File menu. I cannot do the first, since the disk has not yet arrived and will not for ten days or so. And when I try the second I find that permissions are greyed out and cannot be changed. I tried putting DiskWarrior onto a flash drive, with the same result. Then I put it onto my iMac 8,1 running OS10.6.8 as a target disk using Firewire, with the same result again. I'm stuck. What now?