I am totally confused. All I am trying to do is to erase all my previously deleted files using Eraser.
I have downloaded the file and from there have not a clue what to do?
Can anyone help me through all this?
If the erase showed 'completed with errors', you need to look at the log (details in the post I referred you to). Chances are that it's some sort of permissions issue. The task will be in the Schedule, so you could try running Eraser as Administrator (again details in the post I referred you to), and then running the task again. That shouldn't be necessary with the Recycle Bin, but it does depend to some extent on what is in there. Another approach that sometimes works is to empty the Recycle Bin normally, and then use Eraser to erase the free space on the drive.
There is also a possibility that some files (or shadow directory entries) absolutely refuse to be deleted or erased. If that happens to you, please come back for further advice.
Erasing emails is a different issue, and will depend to some extent on what email application you are using. Emails are typically not files in their own right but entries in a database, and so cannot be dealt with by normal file erasing. The best approach is normally to delete the messages you no longer require, compact the email folders in the email application (most programs have this facility), then again erase the free space on the drive. Even so, among file recovery programs, Recuva seems to have a marvellous (or irritating, depending on your intentions) facility for recovering deleted emails seemingly out of nowhere (shadow copies may play a part in this process), and its normal facility for overwriting files does not work with these email stores.
Perhaps the only way to clear emails from your system is to backup the store files after compacting them, erase them and the free space on the drive and then restore them. Joel may have a better idea.