MS-DOS in Windows 9x

Windows 95, Windows 98, and Windows Me included versions of MS-DOS that included major changes to improve cooperation with the Windows environment. These versions internally continued the original MS-DOS versioning, although they use the respective Windows version branding. They were never available as standalone products, although such unofficial repacks exist and tend to be mislabeled as actual standalone versions.

MS-DOS 7.00
MS-DOS 7.00 is included as part of Windows 95 RTM and is not available as a standalone product. MS-DOS 7.0 was originally a separate project, but later combined with the Chicago project to act as the basis for booting and running real-mode applications under Windows. and  were combined into a single file, initially called   but later renamed to , while   was changed into a configuration file. Also introduced was support for long file names on the FAT file system. Although MS-DOS 7.00 is a part of Windows 95, older versions of Windows can also run on unmodified MS-DOS 7.00 extracted from Windows 95 RTM.

The original MS-DOS 7.00 planned to add features like multi-tasking, networking, and better support to MS-DOS 6.x for users who preferred the command-line interface and highly price conscious OEMs. The project started roughly around the same time as Chicago. It is unknown whether any builds were distributed to testers or developers but there are evidence suggesting builds were made. In Windows 95 build 189,  has the branding of MS-DOS 7.00 suggesting MS-DOS 7 was still under development as a separate product in late 1994.

Several fake builds of this version have been circulating on the Internet. Most of those fakes were made by modifying files from early Chicago builds and adding files from other versions of MS-DOS.

MS-DOS 7.10
MS-DOS 7.10 is included with Windows 95 OSR 2.x and Windows 98. This version of MS-DOS includes FAT32 support and improved CD-ROM integration. It was never released as a standalone product, but can be extracted from Windows 95 OSR 2.x and Windows 98 without much effort. Older versions of Windows can run on MS-DOS 7.10, however there are problems.

There are minor changes between MS-DOS 7.10 from Windows 95 OSR 2.x and Windows 98, mainly the branding.

This version of MS-DOS can be obtained officially by upgrading from Windows 98 Second Edition to Windows 2000 Professional. The directory MSDOS7 will be created with all MS-DOS 7.10 system files on the hard drive along with BOOT.DOS and BOOTSECT.DOS.

China DOS Union repack
An unofficial repack of the MS-DOS subsystem in Windows 98 was made by the China DOS Union in 2003 and is often mislabeled as an actual official release of MS-DOS 7.10. The system includes various optional add-ons which install additional third-party programs and graphical shells on top of MS-DOS.

MS-DOS 8.00
MS-DOS 8.00 was included with Windows Me and is the final version of MS-DOS. When installed with Windows, it removes the ability to use real mode MS-DOS without Windows as it skips processing of  and. However, this limitation is not present when an MS-DOS startup disk is created from the user interface or the MS-DOS prompt. This version is also used for the MS-DOS startup disk option in Windows XP through to Windows 8.1.