Timeline: Evolution of a software giant

April 4 1975
Seattle natives Bill Gates, aged 19, and Paul Allen, 22, create Microsoft computer company in Albuquerque, New Mexico, for the purpose of selling BASIC language interpreter for Altair 8800 computer system. Gates drops out of Harvard to start the company

January 1979
Microsoft relocates to Seattle suburb of Bellevue, Washington

June 1980
Steve Ballmer, 24, a former Harvard classmate of Gates, recruited as a business manager

1980
Microsoft releases Xenix, its first operating system, based on IBM’s Unix

1981
IBM hires Microsoft to create an operating system for its new personal computers

1981-83
Microsoft markets MS-DOS operating system to IBM clones, emerging as prominent software company

1983
Microsoft enters hardware and publishing markets

1983
Allen resigns from Microsoft to seek treatment for Hodgkin’s disease. The treatment is successful and Allen keeps board position

August 1985 Microsoft partners with IBM to create OS/2 operating system

November 1985
Microsoft releases first retail version of Microsoft Windows, an operating system based on MS-DOS

February 1986
Microsoft relocates to Redmond, Washington, the company’s present-day hometown

March 13 1986
Microsoft shares float, raising $61m

August 1989
Microsoft releases first Microsoft Office program

May 1991
Gates cancels OS/2 partnership with IBM; Windows emerges as operating system of choice for PCs

March 1992
Microsoft releases Windows 3.1, which sells 2m copies in two months

1993
Windows is world’s most popular operating system

August 1995 New Windows 95 operating system, aimed at consumers, sells 1m copies in four days. Microsoft launches MSN online portal as a competitor to America Online

July 1996
MSNBC cable channel launched with NBC

1997
Release of Microsoft Office 97 and Internet Explorer 4.0

October 1997
US Justice Department files legal motion saying bundling of Windows and Internet Explorer on Apple computers violated 1994 non-bundling agreement. Government sues Microsoft the following May for anti-competitive practices

1998
Ballmer named president of Microsoft; Gates remains chairman and CEO. Windows 98 released

January 1999
Microsoft leads FT 500 list of world’s biggest companies. Today, with a market capitalisation of $281bn, Microsoft ranks third after ExxonMobil and General Electric

January 2000
Gates transfers chief executive role to Ballmer, retaining chairmanship and taking role of chief software architect

April 2000
Decision in United States v Microsoft forces Microsoft to split into two units: one to produce operating system, the other to produce software components. Microsoft appeals decision in September 2000

January 2000
Gates founds Bill & Melinda Gates Foundation

November 2000
Allen resigns board position

October 2001
Microsoft releases Windows XP operating system

November 2001
Justice Department, having decided not to pursue split-up, offers proposed settlement to force Microsoft to share information with third parties. Most of the settlement would be accepted in November 2002

November 2001
Microsoft releases Xbox gaming console

April 2002
Microsoft reorganises into seven independent business entities, later further reorganised into three divisions: Platform Products & Services; Business; and Entertainment and Devices

March 2004
European Commission finds Microsoft guilty of violating EU competition rules

July 2005
Microsoft announces launch of Windows Vista, set for release in 2007

June 15 2006
Gates announces he will end day-to-day role at Microsoft in July 2008