Windows 1 (first Windows released in year 1985 running on Tesla SMEP PP06 (IBM PC XT Clone) with 640 KB RAM 2x360 KB 5,25" FDD, 42 MB MFM HDD (Seagate ST251) and Hercules Graphic Card. This computer in pictures: https://photos.app.goo.gl/euFdeDBSLyJe4ddN8