When Compaq introduced the first PC based on Intel's new 80386 microprocessor, the Compaq Deskpro 386, in 1986, they began a period of increasing performance leadership over IBM, who were not yet using this processor. An IBM machine eventually reached the market seven months later, but by that time Compaq was the 386 supplier of choice and IBM had lost its image of technical leadership.
For the first three months after announcement the Deskpro 386 shipped with Windows/386. This was a version of Windows 2.1 adapted for the 80386 processor. Support for the virtual 8086 mode was added by Compaq engineers.