Undeleting files: When MS-DOS deletes a file, it replaces the first character of the filename with a different character; This character is ASCII 229. A file beginning with this character is a sign to MS-DOS that the file has been deleted, can be overwritten, and should not be listed in any directory listings. The way to undelete a file is simply to change this character to something else, so DOS stops thinking that the file has been deleted. This same procedure can be used to undelete directories, and once the directory has been undeleted, you may also be able to undelete the files that used to be within that directory.