When you delete sensitive files using standard Windows ‘Delete’ command, the operating system does not shred contents of the documents from hard drive, it just marks disk space, earlier occupied by the files, as ‘free’. To completely remove all the traces of the earlier deleted files, use Wipe Free Space command to wipe free space on the disk, where these files were stored.
In order to clean free space on a hard drive, BCWipe creates temporary files with wiping pattern inside. These temporary files overwrite old data written to the disk. Using a smart technology, BCWipe can overwrite free space without allocating all available disk space at once, it means that the drive never gets 'Low disk space' condition.
To wipe free space on a disk, run Wipe Free Space command from Windows Explorer using a pop-up menu. Right-click on the drive item you want to wipe: this will bring up the menu that includes Wipe Free Space. The following picture illustrates how to run the command:
The top part of the window reports information about the disk - total size, file system, free space. Click if you want to enable Reserved Space feature and assign the free space threshold. See Reserved Space chapter for more details.
Choose the desired wiping scheme in Scheme drop-down list. Click to see the wiping scheme patterns and/or to create a custom scheme.
BCWipe reports Estimated wiping time at the bottom part of the window. When BCWipe estimates the time, it assumes that the writing speed is some average value and calculates how long it will take to wipe the free space.
Click to make BCWipe "try" the writing operation for this specific disk to make more exact estimation.