Development and History
Windows 1.0 was Released November 20 1985, with the product codename Interface Manager first announced November 1983).
Windows 1.0 was a DOS GUI, and was able to work with several programs at same time, with the user possessing the ability to easily switch, without having to quit, and start individual applications.
One of the main drawbacks was, that it was limited to 640Kb memory. A Drawback now, but 640Kb was enough for all systems, back then.
Windows 1.0 was considered a commercial flop - Microsoft sales did not even break even. As it was aimed at the Business User, home users never saw this version.
Released November 1985
Released in August 1986
Release in April 1987