Windows 1.0/Preliminary Version 0.50

From BetaArchive Wiki
The splash screen

Preliminary Version 0.50 is a pre-release build of Microsoft Windows 1.0. A total of 4 files, namely CGA.LGO, WINOLDAP.GRB, WIN256.COM, and a part of WIN100.EXE from this build were recovered from Premiere Edition by BetaArchive members jb881122 and ComputerHunter in June 2020.[1][2]