MS-DOS 3.3 released in August 1987 was extended to support IBM PS/2 computer. It now supported multiple partitions alowing harddisk drives bigger then 32 MB. Also, 3.5-inch floppy disk drives support, and character sets for different languages were added.

MS-DOS 3.3 was a very popular version and worked well on most hardware. It followed by version 4.0, which was a failure due to large number of bugs and many programs refusing to run on it.