The clicking is the head scanning back and forth. Sounds like you drive may be going bad. Best way to try to fix it is to eliminate the bad blocks, if possible, by formating with the option to write zero's to the entire disk. This will map out and mark any bad blocks so they will not be used. This failing you will need to remove the battery and look in the compartment for the exact Book you have and we can direct you to the directions for replacement.