Windows 2.1 is a major release of Microsoft Windows.
It was released to manufacturing on May 27, 1988, as a successor to Windows 2.0.
It was released with two different variants with differing CPU compatibility,
also known as Windows/286 and Windows/386,
so the versions are considered to be similar to its predecessor.
In comparison, the Windows/386 variant is considered to be better than the 286 one,
since it provides support for EMS emulation
and is designed to use both conventional and extended memory.
Changes to the user interface did not occur in this version, and rather,
its performance was increased and enhanced memory management was added.
The version is also noted to be the first one to require a hard disk drive.
A minor update version, Windows 2.11, was released in March 1989.
Enhancements that were introduced were considered to have improved the operating environment,
while the Windows/386 variant was noted to have a good level of functionality.
It was considered to be one of the most popular 80386-based systems.
The sales of Microsoft Windows continued to go up after its release, and in May 1990,
it was succeeded by Windows 3.0,
which is considered to be the first Windows version
to perform well both critically and commercially.
Microsoft ended its support on December 31, 2001.