I have a 2006 13" macbook running 10.6.8. All of a sudden, I log into my account, but the desktop has no icons, no dock, and no menu bar. The guest account functions normally. Additionally, when starting the macbook in target mode while attached to my iMac running Mavericks, I cannot access the macbook. It appears on the iMac desktop, but when I double click its icon I get the following error message: The folder MacBook HD cant be opened because you dont have permission to see its contents. What happened and how do I remedy it?