Attempting tp provide in easily portable form a useful and comprehensive guide to the MS-DOS operating system for computers of the PC class, this book also has some background information on the origins of MS-DOS. The book mainly addresses the user of DOS, dealing with the day to day control of the loading and saving of programs and data, backing up files, checking files and disks, and the integrity of the data. How to set up the computer using the AUTOEXEC.BAT file and the CONFIG.SYS file is included also, and while the emphasis is on the use of a machine with a hard disk, the users of single/double floppy machines will also find much that is applicable.