Windows 0.5

Windows 0.5, originally Microsoft Interface 1.5, is a version of Windows released in 1983 that mainly focused on improving Windows 0.1. It was released in response to the lukewarm reception Windows 0.1 got.

Features
It has most of the same features as the previous version, but instead of using a hacky modified text mode that only worked on certain graphics cards with the previous version, Windows 0.5 opted to use CGA witch increased compatibility in exchange for much uglier colors. It also features a game known as Reversi, which would be included with Windows up until Windows 3.0.