Bangalore: The first independent version of the Microsoft Windows version 1.0 released on 20 November 1985 was a Windows graphical user interface (GUI) for its own operating system (MS-DOS), which had shipped for IBM PC and compatible computers since 1981.

The foundation for the world’s software giant rather had a humble beginning. Paul Allen and Bill Gates, as computer enthusiasts were immediately drawn to implementation of the programming language BASICS for the microcomputers, after coming across the January 1, 1975 issue of the Popular Electronics which demonstrated the Altair 8800 a microcomputer. Gates called the creator of the new microcomputer, MITS (Micro Instrumentation and Telemetry Systems) offering a demonstration of their interpreter for Altair, in order to win the contract.      

Allen and Gates had neither an interpreter nor an Altair system, yet in the eight weeks before the demo they developed an interpreter. When Allen flew to Albuquerque, New Mexico to meet with MITS, the interpreter worked and MITS agreed to distribute Altair BASIC.