Recuva won't delete thumbnails in Recuva Bug Reporting Posted November 11, 2018 · Report reply Did you wipe free space using Drive Wiper? Drive Wiper overwrites the deleted records in the MFT so Recuva should return a long list of null, or ZZZ.ZZZ file names. All these null files should be a few hundred bytes in size, and be contained in the MFT. There shold be no clusters allocated to them. Are you still seeing the thumbnails? If you are, these should be found with a deep scan, and will have a numerical file name assigned instead of the actual filer name. These will not be overwritten by a live file, and can be securely deleted (which is just another overwrite). If you are seeing the thumbnails, go to the Info panel as described above and post a screenshot of what is there.