The first release version of Windows 2.0 was actually numbered 2.03

Windows 2.03 was a 16-bit Microsoft Windows graphical user interface-based operating environment that superseded Windows 1.0 Windows 2.03 was supplemented by Windows/286 and Windows/386 in 1988. Windows 2.03, Windows/286, and Windows/386 were superseded by Windows 3.0 in May 1990.