A Harvard University dropout, Bill Gates co-founded Microsoft with Paul Allen in 1975. By 1980, he had licensed his MS-DOS operating system to IBM for its inaugural personal computer. Microsoft's Windows 95 computer operating system and Internet Explorer browser debuted in 1995 at the dawn of the Internet age. On Oct. 26, 2012, Microsoft releases its latest version of the operating system, Windows 8. Today, Gates is considered to be the world's richest private citizen with an estimated worth of 90 billion dollars.
Microsoft Chairman and CEO Bill Gates, left, talks about the release of Windows NT 4.0 operating system for businesses with Jim Allchin, senior vice president of desktop and business systems division, at a media reception in Bellevue, Wash.
Microsoft Corp. Chairman and Chief Software Architect Bill Gates gestures as he stands in front of a huge fake laptop computer during the launch of Windows 2000 in San Francisco. Windows 2000 is the upgrade for Windows NT and Windows 95-98 for business computing.
Microsoft chairman and chief software architect Bill Gates addresses members of the media during a news conference unveiling Windows XP in Seattle. Windows XP, built on the enhanced Windows 2000 engine, featured a new look and extended personal computing services, including uniting PC's, devices and services.
Microsoft chairman Bill Gates stands in Times Square to promote the new Windows XP operating system in New York. Gates touted the software as the harbinger of a new era in more Internet-centric computing. "Today it really is actually the end of the MS-DOS era," Gates said.
Steve Ballmer, CEO of Microsoft, shown on a video monitor, introduces Windows Vista, Microsoft Office and Exchange Server 2007 at a launch event for business users and software developers in New York.
Cassidy Mason, 12, center, with her mother Robin, left, of Peoria, AZ, shows Microsoft CEO Steve Ballmer her favorite features of the Window Vista operating system during an appearance at a midtown Manhattan store to promote the first day of sales of Windows Vista.
Chris Liddell, CFO of Microsoft Corp., yells as he tries to fire up a crowd of Microsoft employees before the start of a rally to celebrate the release of Windows 7 at the Microsoft Campus in Redmond, Wash. During the gathering, Liddell pushed a button to officially start the NASDAQ stock market trading day.
Microsoft CEO Steve Ballmer comments on the Windows 8 operating system before unveiling its new Surface, a tablet computer to compete with Apple's iPad at Hollywood's Milk Studios in Los Angeles Monday. The 9.3 millimeter thick tablet comes with a kickstand to hold it upright and keyboard that is part of the device's cover. It weighs under 1.5 pounds. (June 18, 2012)