Basically what I did so far is to go to Disc Utility and run the "erase free space" 7 times. When I returned I discovered there are still docs in the HD.
Open the Terminal application in your Utilities folder. At the prompt enter or paste the following:/usr/bin/drutil eject.
If this fails then try this:Boot the computer into single-user mode. At the prompt enter the same command as used above. To restart the computer enter "reboot" at the prompt without quotes.