Windows/286 2.1

Windows/286 2.1 is an RTM build of Windows 2.x. It was released to manufacturing in 1988 and is designed to take advantage of the HMA (High Memory Area) feature of the Intel 80286 (although it remained compatible with both the 8086 and 8088). It was marketed as "Windows/286" to denote it from the 80386 variant, which leads to some confusion as some vendors sold Windows/286 with machines running on an 8086/8088.