Attention! Wiping files or free disk space on SSD devices is not possible in most cases. Read the File Erasure on SSD and HDD devices page for details.
R-Wipe & Clean disables wiping files and free disk space on such devices by default. You may enable it, but you should understand what you are doing.
Simply deleting a file does not mean that the data of this file are gone for good. When you delete a file, even when the Recycle Bin is disabled, Windows writes some information on the disk that this particular file should be treated as unneeded, and its space may be allocated for other file. Until data from the next file are written over the deleted one, the deleted data may be easily recovered using inexpensive and easily available data recovery utilities. To completely destroy the data, it must be overwritten, sometimes not once. Such process is called wiping . R-Wipe & Clean wipes files, making their recovery virtually impossible. It also wipes stored names of deleted files, file's alternate data streams, cluster tips, and records of small files stored directly into NTFS Master Table.
Even if you have removed all deleted files, that does not mean that no data from them remain on your hard drive. If you have rewritten your files many times, for example, while editing, some previous copies of the files may still remain on the disk without a slightest notice of their existence. Also, Windows constantly writes and deletes its own temporary files on disks. Such files are not visible to users, but may contain some data from your own files and programs. Such pieces of your data still remain even after you format the disk. There are special data recover utilities that analyze unused space on disks and can restore many files that you believe to be completely wiped and deleted. R-Wipe & Clean wipes unused disk space, making such analysis of disk space useless.
You may wipe unused disk space on a single disk using the Wipe Free Space with R-Wipe & Clean command on the disk's shortcut menu, or on several disks at once on the Free Drive Space panel.