MS-DOS Version History

This is a list of MS-DOS versions released to the public.

Microsoft DOS was released through the OEM channel, until Digital Research released DR DOS 5.0 as a retail upgrade. With PC DOS 5.00.1, the IBM-Microsoft agreement started to end, and IBM entered the retail DOS market with IBM DOS 5.00.1, 5.02, 6.00 and PC DOS 6.1, 6.3, 7, 2000 and 7.1.

Localized versions of MS-DOS existed for different markets. While Western issues of MS-DOS evolved around the same set of tools and drivers just with localized message languages and differing sets of supported codepages and keyboard layouts, some language versions were considerably different from Western issues and were adapted to run on localized PC hardware with additional BIOS services not available in Western PCs, support multiple hardware codepages for displays and printers, support DBCS, alternative input methods and graphics output. Affected issues include Japanese (DOS/V), Korean, Arabic (ADOS 3.3/5.0), Hebrew (HDOS 3.3/5.0), Russian (RDOS 4.01/5.0) as well as some other Eastern European versions of DOS.

MS-DOS 1.x

DOS 1.x was very limited in what it could do. It could start applications (.COM and .EXE), and process batch files (.BAT). DOS 1.0 worked with 160KB floppies and did not support folders (all files had to be in the root). The command interpreter supported the following commands:

• DIR, TYPE, COPY, ERASE, RENAME
• PAUSE, REM

No pipes, redirection, or device drivers were supported. The DOS API in 1.0 was very limited.

MS-DOS 1.25, the equivalent of PC-DOS 1.10, was the first version licensed to OEMs beyond IBM or Seattle Computer Products.

Some vendors labeled their versions of MS-DOS with different names and version numbers. All of the versions here are believed to be based off of MS-DOS 1.25, even if the vendor called it something else.

• Version 1.10 (OEM) – possible basis for IBM's Personal Computer DOS 1
• Version 1.11 (OEM) – possible basis for IBM's Personal Computer DOS 1.0
  • Compaq-DOS 1.12, a Compaq OEM version of MS-DOS (1.25 or higher)
• Version 1.14 (OEM) – possible basis for IBM's Personal Computer DOS 1.0
  • Zenith Z-DOS 1.19, a Zenith OEM version of MS-DOS (1.25 or higher)
• Version 1.24 (OEM) – basis for IBM's Personal Computer DOS 1.1
• Version 1.25 (OEM) – basis for non-IBM OEM versions of MS-DOS, including SCP MS-DOS 1.25

MS-DOS 2.x

DOS 2.x adds support for sub-directories and larger (as in 10 MB) disks, FAT16, user installable device drivers, and tree-structure filling system. It was also the first version to support folders.

• Version 2.0 (OEM), First version to support 5.25-inch, 360 kB floppy drives and diskettes.
• Version 2.1 (OEM)
• Version 2.11 (OEM)
  • Altos MS-DOS 2.11, an Altos OEM version of MS-DOS 2.11 for the ACT-86C
  • TeleVideo PC DOS 2.11, an TeleVideo OEM version of MS-DOS 2.11

MS-DOS 3.x

• Version 3.0 (OEM) – First version to support 5.25-inch, 1.2 MB floppy drives and diskettes.
• Version 3.1 (OEM) – Support for Microsoft Networks
• Version 3.2 (OEM) – First version to support 3.5-inch, 720 kB floppy drives and diskettes.
• Version 3.21 (OEM)
• Version 3.22 (OEM) – (HP 95LX)
• Version 3.25 (OEM)
• Version 3.3 (OEM) – First version to support 3.5-inch, 1.44 MB floppy drives and diskettes (OEM)
• Version 3.3a (OEM)
• Version 3.31 (OEM) – supports FAT16B and larger drives

MS-DOS 3.00

DOS 3.0 adds support for FAT16 partitions up to 32MB, 1.2MB floppy drives, and the IBM AT internal clock.

MS-DOS 3.0x is extremely rare. After the release of IBM PC-DOS 3.0, Microsoft dragged their feet providing MS-DOS 3.x to other OEMs, possibly to appease IBM. Most OEMs didn't get MS-DOS 3.x until 3.1.

Apricot and Compaq MS-DOS 3.0x versions are known to exist. Zenith and AT&T are suspected to exist.

MS-DOS 3.10

DOS 3.10 adds support for networking, used by IBM PC Net and Microsoft Networking products.

Note: Zenith "Z-100" is a non IBM PC compatible, while "Z-100 PC" is a completely different PC compatible machine.

MS-DOS 3.20

Microsoft DOS 3.2 is the first release offered as a "vanilla" boxed set directly to consumers, instead of just OEMs.

This version adds mainstrem support for 720K 3.5" floppy drives, although some 2.x OEM versions also supported 720K disks.

A new RAMDRIVE.SYS supports creating a ram disk in conventional, EMS, or XMS memory.

MS-DOS 3.21

Although a minor update, 3.21 was sold with a large number of OEM machines.

DOS 3.21 primarily fixes small bugs, and adds support for IBM Enhanced/IBM Convertible keyboards.

MS-DOS 3.30

MS-DOS 3.30 adds support for 1.44mb floppy drives. and extended hard disk partitions.

MS-DOS 3.30 was a very popular version of MS-DOS. Due to the problems with 4.0, and 3.31 only being available via OEM, many users stuck with 3.30 unless they needed larger hard drive support.

MS-DOS 3.31

MS-DOS 3.31 was only sold through a few OEMs, mainly Compaq.

This version adds support for hard drives up to 512MB.

It also does not use as much conventional memory as DOS 4.x or later, making it a good choice for 8088/8086 based computers.

MS-DOS 4.0 (IBM-developed)

MS-DOS 4 added support for hard drive partitions up to 2GB. It used much more of the base 640K, and was somewhat buggy.

Microsoft had long planned that MS-DOS "4" would be a multitasking-capable operating system, but IBM had insisted on creating a new version of regular DOS for use with their PS/2 computers. The below versions, as released to the consumer market, are based on DOS 3.3x and IBM's PC-DOS 4.0 enhancements. Although essentially scrapped, some narrow European markets did receive Microsoft's Multitasking MS-DOS 4.0

Microsoft's initial 4.00 release (File dates 10/6/1988) was quickly followed up by 4.01, making this an uncommon version. To add to the confusion, most OEMS badged their 4.01 disks as "4" or "4.0".

Includes a graphical/mouse interface. It had many bugs and compatibility issues.

• Version 4.00 (OEM) – First version to support a single hard disk partition that is greater than 32 MiB and up to a maximum size of 2 GB
• Version 4.01 (OEM) – Microsoft rewritten Version 4.00 released under MS-DOS label but not IBM PC DOS. First version to introduce volume serial number when formatting hard disks and floppy disks (Disk duplication also and when using SYS to make a floppy disk or a partition of a hard drive bootable).
• Version 4.01a (OEM)

MS-DOS 5.x

MS-DOS 5 introduced numerous new features and was a flagship release for Microsoft. A full screen text editor EDIThas replaced the former line editor EDLIN supplied since the early days of DOS. Microsoft QBasic also shipped in DOS 5 replacing GW-BASIC. MS-DOS 5 also supported 2.88MB 3.5" floppy disks as well as hard disks up to 2GB in size. The memory management was rewritten to allow DOS to utilize the High Memory Area and Upper Memory Area to reduce its usage of conventional memory. Numerous bugs were noticed shortly after launch which lead to the 5.0a update.

This release of DOS was the last of the collaboration between Microsoft and IBM and as a result will be the last result where PC-DOS and MS-DOS are near-identical. This was also the version of DOS used in the OS/2 and Windows NT virtual DOS machine.

When MS-DOS 5 was released the entire market had become dominated by IBM and compatible systems, so specific OEM versions of DOS for machines not using an IBM BIOS were not shipped as in prior releases.

• Version 5.0 (Retail) – includes a full-screen editor. A number of bugs required re issue. First version to support 3.5-inch, 2.88 MB floppy drives and diskettes. Hard disk partitions greater than 32 MiB and up to a maximum size of 2 GB was now provided by the MS-DOS kernel.First version to load portions of the operating system into the high memory area.
• AST Premium Exec DOS 5.0 (OEM) – a version for the AST Premium Exec series of notebooks with various extensions, including improved load-high and extended codepage support
• Version 5.0a (Retail) – With this release, IBM and Microsoft versions diverge
• Version 5.50 (Windows NTVDM) – All Windows NT 32-bit versions ship with files from DOS 5.0

MS-DOS 6.x

MS-DOS 6.0

MS-DOS 6.0 includes many new utilities and features, including a disk defragmenter, disk compression, anti-virus, a new backup system, and pc-pc file transfer tools. It was heavily criticized as buggy by the media, primarily due to file corruption issues with DoubleSpace and the lack of tools to repair such issues.

Note that the boot sector OEM ID of "MSDOS6.0" is correct and genuine. Microsoft reverted to using "MSDOS5.0" on later disks.

MS-DOS 6.20

Microsoft intentionally skipped "6.1" to prevent confusion with IBM's independently produced PC-DOS 6.1. Microsoft also made a free/inexpensive 6.0 -> 6.2 step up kit available.

This update corrects some major bugs in DoubleSpace, introduces ScanDisk, adds automounting of compressed floppies, and a tool to uncompress DoubleSpace compressed drives.

MS-DOS 6.21

This version was specifically released to remove DoubleSpace due to legal injunction. Their replacement "DriveSpace" was not yet ready.

MS-DOS 6.22

Microsoft DOS 6.22 was the last standalone version from Microsoft. It was also the last from Microsoft to run on an 8088, 8086, or 286.

6.22 adds DriveSpace, a replacement for DOS 6.20's DoubleSpace drive compression that was removed in 6.21.

There's a really detailed tutorial located at http://legroom.net/howto/msdos that gives tips on how to customize DOS. We suggest you follow this tutorials suggestions for setting up and customizing DOS. However, if you're installing to a virtual machine, writing the disk images to actual floppies isn't really necessary.

• Version 6.0 (Retail) – Online help through QBASIC. Disk compression, upper memory optimization and antivirus included.
• Version 6.2 – Scandisk as replacement for CHKDSK. Fix serious bugs in DBLSPACE.
• Version 6.21 (Retail) – Stacker-infringing DBLSPACE removed.
• Version 6.22 (Retail) – New DRVSPACE compression.

MS-DOS 7.x

• Version 7.0 (Windows 95, Windows 95A) – Support for VFAT long file names and 32-bits signed integer errorlevel. New editor. JO.SYS is an alternative filename of the IO.SYS kernel file and used as such for "special purposes". JO.SYS allows booting from either CD-ROM drive or hard disk. Last version to recognize only the first 8.4 GB of a hard disk. The "VER" internal command prompt reports the Windows version 4.00.950.
• Version 7.1 (Windows 95B – Windows 98 – Windows 98SE) – Support for FAT32 file system. Last general purpose DOS to load Windows. The "VER" internal command prompt reports the Windows version 4.00.1111, 4.10.1998 or 4.10.2222

MS-DOS 8.x

• Version 8.0 (Windows ME) – Integrated drivers for faster Windows loading. Four different kernels (IO.SYS) observed.^{[nb 4]} The "VER" internal command prompt reports the Windows version 4.90.3000.
• Version 8.0 (Windows XP) – DOS boot disks created by XP and later contain files from Windows ME. The "VER" internal command prompt reports the Windows version 5.1.

Other Versions

MS-DOS 4.0 (multitasking) and MS-DOS 4.1

A separate branch of development with additional multitasking features, released between 3.2 and 3.3, and later abandoned. It is unrelated to any later versions, including versions 4.00 and 4.01 listed below.

MS-DOS Mobile 1.0 (Windows Phone)

This version was an April Fools' Day joke in 2015 by Microsoft. It is available on the Microsoft Store.