Microsoft was founded in 1975 by Bill Gates and Paul Allen.
The two childhood friends created the company after seeing the Altair 8800, an early personal computer, featured on the cover of Popular Electronics. They wrote and licensed a version of the BASIC programming language for the Altair, establishing the business in Albuquerque, New Mexico, on April 4, 1975.
Microsoft's major early breakthrough came when IBM selected MS-DOS for its IBM PC, released in 1981. Microsoft later became dominant in personal-computer operating systems and productivity software through Windows and Microsoft Office. Its expansion into enterprise software, cloud computing, gaming, and professional networking helped make it a global market-cap leader.
The year 1975 is sometimes confused with 1981, the year of the IBM PC launch, or 1985, when the first retail version of Windows appeared. Those dates mark important milestones, but they are not Microsoft's founding year.