IBM PC DOS is a DOS system for the IBM Personal Computer and compatibles, manufactured and sold by IBM from the 1980s to the 2000s.

In March of 1983 IBM released PC DOS 2.0 to support IBM Personal Computer XT. The new OS had support for double sided floppy disks and hard drives up to 10MB. PC DOS came on two 180 kB 5.25-inch disks or one double-sided 360 kB 5.25 inch floppy disk.

PC DOS 2.0 was updated to version 2.1 in October 1983.