Shredder is a Windows NT(TM) or Win32 drag and drop application that completely wipes out any files or directories that are dropped onto it. DO NOT even think of retrieving a file after Shredder has done its job on it. The file is completely overwritten with 0x00, then 0xFF, and finally 0x00.  Then its length is set to 0.  It seems even though the file is renamed to 0x255 before any of this wiping is done NT still retains the orginal filename after all these operations (although the length is zero and the file is listed as being destoyed) when trying to undelete the file with most file undelete utilities (although none of them could recover any part of the Shredded file).  Have fun.  Shredder is Public Domain, FREE !; and  shows a machine shredding a 5.25" diskette while it is doing its job.  
To use  Shredder, start up Shredder, select files or directories in file manager and drag them onto the Shredder Icon/Bitmap (Note: directories must be empty to be deleted and are not Shredded). Double clicking on Shredder's Icon/Bitmap will close it, and clicking on it with the right mouse button will display its about box and a selection of whether or not it will always be on top.