MS-DOS 5.00

MS-DOS 5.0 adds support for 2.88MB 3.5" floppy disks and harddrive partitions larger than 32MBs, up to a max of 2GB. It also includes HIMEM.SYS for managing upper memory blocks and the high memory area, as well as replacing the older EMM386.SYS with the more well known EMM386.EXE. As a result, it is also the first version of MS-DOS that supports loading parts of itself into the high memory area with the DOS=HIGH parameter. MS-DOS 5.0 is also the first DOS to support upgrading the existing installation instead of creating a new one. Microsoft also licensed the commands MIRROR, UNDELETE, and UNFORMAT from Central Point Software. The "/?" parameter was also added to all dos commands for program help and command syntax. This is also the first DOS to introduce EDIT, replacing EDLIN, and QBASIC, which replaced both GW-BASIC and IBM Cassette BASIC, the latter of which rendered IBM PC-DOS from this point forwards fully functional on non-IBM hardware and effectively just an OEM rebrand of MS-DOS. The only other OEM rebrand of MS-DOS 5 was AST's Premium Exec DOS 5.0 for their Premium Exec series of laptops, which included an improved LOADHIGH and extended codepage support among other system specific extensions.

MS-DOS 5.0 is also the version of DOS emulated by the Windows NT and OS/2 virtual DOS machines.