I ' m not aware of Freeraser but CCleaner a free program has the ability to wipe free space . It can run 1 , 3 , 7 or 35 passes , can do this by wiping alternate data streams if required and has a setting to wipe cluster tips afterwards . And a setting to overwrite free space in the master file table 1 basic pass of wiping your hard drives free space will make all deleted files unrecoverable except to theoretical techniques which have only worked in labs on tiny amounts of data . 3 wipes with cluster tips and file table and alternate streams enabled will make it so the hard drive cannot be distinguished from one which didn ' t have the data on at an atomic level . 35 is madness and takes a long time . Worth noting , wiping free space too often is a bad idea on SSD .