Windows 1.0 is the first major release of Microsoft Windows, a family of graphical operating systems for personal computers developed by Microsoft. It was released in the United States on November 20, 1985. The development of Windows 1.0 began after Bill Gates, co-founder of Microsoft, saw a demonstration of a similar software suite called Visi On in 1982. Some of the features introduced in Windows 1.0 include a new Start Menu and user interface, multifactor authentication security, compressed system files, and the introduction to graphical user interface (GUI) operating systems. Windows 1.0 marked the beginning of the widespread acceptance and adoption of Microsoft's Windows versions.