You will need to restore the file before you can delete it again. If the file is still in your recycle bin you can right-click it and select recover to restore the file, and then delete it again with SparkTrust Privacy Cleaner.
If the files have already been removed from your Recycle Bin, the only way to shred and overwrite these files is to recover them first then shred them from your system. To recover these files, we suggest using a data recovery program.
Once a file has been deleted from your computer the location is uses on your hard drive is no longer remembered by the Operating System, so SparkTrust Privacy Cleaner cannot overwrite the data.