Yes, I have a Powerbook 520c, and when I start it up the apple icon crashed and two num.bers come up. Showing "I guess" that the problem is in that area. I do not have the disk tools and it has been updated from the original verison of 7.0.1. I have looked all over for a disk tools but I keep getting a message telling me that the operating system is newer and please insert the new disk. My question is, even though my computer does not start up is their anyway that I can format the computer and just reinstall the old 7.0.1 system? Do keep in mind that the computer does not fully startup and I have tried holding down shift, control, delete, and option. I have also tried holding down shift to disable extensions. Thanks for your help, any will help....