I was deleting some items from my Powerbook G4 and now it won't start up. I get the broken folder and question mark, then the grey screen with the apple logo on and a spinning wheel. I cannot boot in safe mode, it will not boot from the install CD and I have tried to reset the pram. I can get into the single user mode where I press S plus apple key and I get the screen with writing on it. The error message I am getting is /system/library/frameworks/security.framework/veresions/A/security and reason image not found. Can anyone please help me with how I can get the mac to start up properly again. Many thanks.