I use a program called perfect disk to defrag my hard drive. It aggressively tries to give me the most contiguous free space. Assuming that the disk has been cleaned up (remove all temp files, etc) then defragged, I would like to then wipe out the free space to make sure anything in the free space is thoroughly obliterated. Then I would use True Image to make a good backup copy of the entire drive. I do not want to wipe out the existing data, such as what would happen if I wiped out the whole partition or hard drive. I just want to thoroughly clean the free space using one of the methods such as the DoD method. Is this program capable of doing just that?