Probably you know that deleted files can be recovered. This is true - anyone can do it using special programs, especially often this operation performed by police, FBI and other agencies. News are full of events that related to legal and illegal data recovery. Many important financial and personal information was recovered and used against human privacy and financial stability. When you delete some file it's not actually removed from the hard disk, it's just marked as "deleted" and the space which was taken by the file marked as "free". However, the contents of the file still exists on your computer until will be partially or fully overwritten by some new file. These "deleted" files may reside on your computer for years, depending on many factors. Thus, recovery of any file technically possible, but anyway you need some luck also. Solution for this problem is to programmatically overwrite all free disk space where content of deleted files was located. In other words: physically wipe free disk space, replace each byte with zeros. This operation on a physical level leaves no chance for recovery. It doesn't make any changes to existing files or programs, so it's completely safe. This is what our program does: it will make deleted files unrecoverable by wiping free disk space, so nobody will be able to restore them.