"This new group of users, providing a growing target
audience for software developers to aim their wares at,
precipitated the enormous hegemony that Microsoft enjoys today on
the desktop. The transition from DOS to Windows was not exactly
smooth, as anyone who can attest to years of fiddling with
HIMEM.SYS settings to get DOS games working under Windows will tell
you. However, it wasn't a burdensome discontinuity either; DOS
line-of-business applications (built in Clipper, dBase, Turbo
Pascal etc.) would, for the most part, safely run under Windows via
emulation.
"I would go as far as saying that without this capability, this
magical attribute of being able to run most of a user's existing
applications, Windows would not have become the dominant platform
that it became. This attribute alone was not enough to cement
Window's market position however. Other GUI environments
(Deskview/X, OS/2 version 2.1) actually had even better DOS
emulation. But without this, Windows would not have been able to
provide enough of a safe and comfortable bridge to transport those
hundred million users across the chasm from DOS."