MS-DOS 7.1 (CDU)

Originally 86-DOS, written by Tim Paterson of Seattle Computer Products, DOS was a rough clone of CP/M for 8086 based hardware. Microsoft purchased it and licensed it to IBM for use with Microsoft's IBM PC language products. In 1982, Microsoft began licensing DOS to other OEMs that ported it to their custom x86 hardware and IBM PC clones.

For IBM-specific releases, please see the IBM PC-DOS product page.

Release notes

MS-DOS "7.1" CDU is a popular custom compilation of MS-DOS and useful utities created by China DOS Union. This custom compilation is designed to aid users who wish to install an advanced MS-DOS environment from CD-ROM or a single set of floppies with minimal hassle.

The underlying version of DOS is the same used under the hood for Windows 95B and Windows 98, which includes support for the FAT32 file system and long filenames.

IMPORTANT: Please be aware that this compilation is not a Microsoft release, but it is provided for your convenience as some people may find it useful.

MS-DOS 7.0 (Windows 95 RTM), MS-DOS 7.1, (Windows 95 OSR2.x and 98), and the crippled MS-DOS 8.0 (Windows ME) were never released by Microsoft as standalone products. does not normally approve of modified/altered builds, however the community has found this customized build to be useful.

Installation instructions

If you want to use this version with Windows 3.x, make sure you disable LFN, as various features of 3.x will generate errors with DOS and will cause programs to unexpectedly crash. This version can be installed via CD or Floppy, both provided below

Product type
Release date
End of life date
Minimum CPU
386 @ 15MHz
Minimum RAM
Minimum free disk space
User interface
Download count
739 (81 for release)


Download name Version Language Architecture File size Downloads
Microsoft DOS 7.1 (3.5) 7.1 (China DOS Union) English 2.74MB 33
Microsoft DOS 7.1 (CD) 7.1 (China DOS Union) English 8.09MB 48


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