From Gregory Braun:
File Shredder 2000 is a file utility that will erase the contents of sensitive files and folders that you specify. Normal file deletion only removes a file's directory entry, but leaves the data contained in the file on your disk drive. File Shredder overwrites the contents of a file and then deletes it. To shred files and folders drag them to the file shredder icon in the same way you would the Recycle Bin. You can also shred files by right-clicking on them from the MS windows explorer and selecting the send to item on the popup context menu.
File Shredder has two file wiping methods available, a two-pass file clearing procedure and an NSA approved seven-pass file erasure method. For normal file deletion operations the two-pass method should be sufficient, but if you want to thoroughly erase a file's contents before deleting it the NSA approved method may be used.