MS-DOS 4 (1985)
| Version of MS-DOS | |
 | |
| Version | 4.00 |
|---|---|
| Release date | 1985 |
Multitasking MS-DOS 4 is the once hyped future of MS-DOS, that Microsoft shelved in favor of OS/2 and IBM's regular DOS 4.x. It was a parallel project to DOS, never released to the regular consumer market, and Microsoft backtracked to base its next consumer release off of DOS 3.3.[1] It was only released by some OEMs in Europe, which is why it's also referred to as "European DOS 4.0".