I have a Power-Book G4, running OS 10.1.5. The other day it stopped reading all external drives along with the internal CD/DVD. Whenever I connect a drive I get a message that it is unreadable and if I wish to initialize the disc. I have tried using a fire wire hard drive, external CD writer (USB) as well as a USB jump drive, all with the same results, yet the USB recognizes the mouse. These drives also work on other Macs. I am unable to mount these drives after repairing with disk utility and am not able to reinstall software because I cannot get it o recognize any drive. I have reset the Pram as well as completely shut down and removed the battery. Any other suggestions.