**David D. Busch** is the author of 24 books, including four best-sellers that concentrate on MS-DOS. Most recently, he revised Que's highly respected *Using PC DOS*, 3rd Edition. The first two-time winner of "Best Book" honors from the Computer Press Association, he has served as a contributing editor and monthly columnist for six different computer magazines. — [MS-DOS: Userʼs Guide](/works/OL18173637W/)