Welcome to the MS-DOS operating system, version 4.0. If you are new at working with operating systems for personal computers, you will want to learn a few basics before you go on to learn about the advanced features of MS-DOS. This MS-DOS® User’s Guide was written to help you understand the fundamentals of using MS-DOS with your personal computer.

Once you have read this MS-DOS® User’s Guide, or if you are already an advanced personal computer user, see the MS-DOS User’s Reference, which presents the features of MS-DOS, and describes each MS-DOS command in detail. In addition, program mers may be interested in the MS-DOS® Programmer’s Reference, which introduces programmers to MS-DOS, and describes all the MS-DOS system calls.