Innovation & Wealth › The information age › Microchips and the personal computer
Bill Gates and Microsoft
b. 1955; Microsoft founded April 1975· Innovator or entrepreneur· Innovators & entrepreneurs
Well documentedSolid records, texts or physical evidence.
Co-founder of Microsoft, whose operating systems and office software ran almost every personal computer for decades.
See it on the Innovation & Wealth map →What happened
Gates left Harvard and in 1975 founded Microsoft with Paul Allen to sell BASIC for the Altair kit computer. In 1980 IBM needed an operating system; Microsoft bought one for about $50,000, renamed it MS-DOS, and licensed it to IBM without exclusivity, so every PC clone paid Microsoft too. Windows and Office followed. License fees on nearly every PC made software hugely profitable, since each extra copy cost almost nothing to make.
Impact on society and the economy
Software became computing's most profitable layer. Gates was often the world's richest person, peaking near $100 billion in 1999 (nearly $200 billion today; estimates vary). Rivals like Netscape lost out.
Fortune, legacy and how we know
Microsoft's filings, the US v. Microsoft trial record (1998–2001), Forbes rich lists, and Gates Foundation reports. In 2025 Gates pledged to give away nearly all his wealth by 2045, when the foundation closes.
Still debated
Whether Microsoft won mainly through better products and timing or through monopoly tactics is still argued; the courts found it illegally protected its Windows monopoly.
Inside this (1)
Connections (4)
▸Intel and Moore's law partnered in the 'Wintel' era with Bill Gates and MicrosoftWell documented
The connection
IBM's 1981 PC paired Intel's 8088 chip with Microsoft's MS-DOS. As clone makers copied the PC, the Intel-chip and Microsoft-software pair became the standard, nicknamed 'Wintel' after Windows. Each new Windows version needed faster Intel chips, and each faster chip ran richer software, a cycle that made both firms dominant and very profitable through the 1990s.
When and how
IBM PC launched August 1981; Compaq's 1983 clone opened the market; 'Wintel' machines dominated PCs from about 1990 to 2010, around 90% of sales at the peak.
How we know
Market-share data, company filings, and the US v. Microsoft and FTC Intel case records document both firms' dominance and interdependence.
Debates
The partners were often rivals: Microsoft supported other chips and Intel pushed its own software. Regulators argued their dominance limited competition; how much consumers were harmed is disputed.
▸Bill Gates and Microsoft licensed MS-DOS for IBM PC and the MS-DOS dealWell documented
The connection
When IBM needed an operating system in 1980, Gates bought one cheaply, adapted it as MS-DOS, and licensed it to IBM while keeping the right to sell it to other computer makers. As PC clones spread, MS-DOS became the standard, making Microsoft rich and Gates a billionaire by 1987, at 31.
When and how
Seattle and Boca Raton, 1980–81; Gates, Paul Allen and Steve Ballmer negotiated with IBM; Tim Paterson had written the original QDOS.
How we know
Contracts and testimony from Seattle Computer Products' 1986 lawsuit against Microsoft, settled for $925,000, and many participants' accounts.
Debates
Whether keeping non-exclusive rights was Gates's shrewd plan or simply IBM's indifference is told both ways.
▸Bill Gates and Microsoft faced antitrust charges in United States v. MicrosoftWell documented
The connection
Gates saw Netscape's browser as a threat that could make Windows less important and pushed to bundle Internet Explorer free with Windows. His internal emails and his combative, evasive videotaped deposition became key evidence. The case dogged Microsoft for years, and Gates handed the CEO job to Steve Ballmer in January 2000.
When and how
Federal court in Washington, D.C., 1998–2001; Gates was deposed in August 1998, questioned by government lawyer David Boies.
How we know
Trial exhibits, including Gates's 1995 'Internet Tidal Wave' memo, and the court's findings of fact document his role.
Debates
Whether the case pushed Gates to step down as CEO and turn toward philanthropy, or he planned that anyway, is unclear.
▸OpenAI and ChatGPT is heavily backed by Bill Gates and MicrosoftWell documented
The connection
Microsoft invested $1 billion in OpenAI in 2019 and about $13 billion in total by 2023, supplying the Azure cloud computing that trained ChatGPT and gaining rights to use OpenAI's models in its products. Gates, no longer on Microsoft's board, advised on the partnership and called GPT-4 the most important technology advance since the graphical interface.
When and how
Redmond and San Francisco; deals in 2019, 2021 and January 2023 under CEO Satya Nadella; after OpenAI's 2025 restructuring Microsoft held roughly 27% of its for-profit arm.
How we know
Microsoft's filings and announcements document the investments; both firms announced the 2025 restructuring terms. Gates's view is in his 2023 essay 'The Age of AI Has Begun.'
Debates
The partnership has been tense: OpenAI added other cloud providers, and the two compete for customers. How much of OpenAI's value Microsoft ultimately captures is uncertain.