This step of the wizard lets you specify which items on your computer you want to delete for good.
The tool displays a list of the items that will be shredded and several buttons which add items to the list.
Add file - add a file to the list, to make sure they are erased for good.
Add drive - add an entire drive to the list. This means all the files and folders on that drive will be deleted for good, so it will be impossible to recover them through an undelete or unformat operation.
Add folder - add a folder to the list
Add free space - add the free space of a drive to the list. This means that the entire free space of a drive will be cleaned of traces of remaining files, so it will no longer be possible to recover any deleted file from that drive.
Remove - remove an item from the list
Be very careful about what you add to this list. After pressing Next, all the items in the list will be deleted for good, and you (or anybody else) won't be able to recover the items in the list.
More information about the File Shredder tool