Windows 1.0, released on November 20, 1985, is a graphical personal computer operating environment. Microsoft had worked with Apple Computer to develop applications for Apple's original Macintosh, the first mass-produced personal computer with a graphical user interface (GUI). It runs as a graphical, 16-bit multi-tasking shell on top of MS-DOS. Its development was spearheaded by the company founder Bill Gates after he saw a demonstration of a similar software suite known as Visi On at COMDEX.
Windows 1.0 was received poorly by some critics. In particular, they felt that Windows 1.0 put too much emphasis on mouse input at a time when mouse use was not yet widespread; not providing enough resources for new users; and for performance issues, especially on systems with lower computer hardware specifications.
Despite these criticisms, Windows 1.0 was an important milestone for Microsoft, as it introduced the Microsoft Windows line. On December 31, 2001, Windows 1.0 was declared obsolete and Microsoft stopped providing support and updates for the system.