From SoftDD Software:
This free software will wipe all open space on your hard drive, so previously deleted files can not be recovered. When you delete files from your pc, they can be recovered from your hard drive as the data is not physically removed. Many files that you thought were long gone, may be recovered by using undelete software, whether they are important documents, pictures or videos, tax documents, audio files, and more. If you are selling, donating, or giving away your pc, then this program is a must. Running this program will fill up and overlay your empty disk space with random characters, and any attempts at file recovery will be useless. This will not harm any existing data, your free space will remain the same when this has completed, but all previously deleted files that you have removed, will be permanently gone so they cannot be recovered. (Runs on all Windows systems.)
What's new in this version:
Version 1.9 features multiple interface changes and changes for latest version of Windows.