Bill Gates is famous for co-founding Microsoft in 1975 and turning it into the company that put a PC on nearly every desk, which made him the world's richest person for a record 18 years. Since stepping back from Microsoft, he's become just as well known for the Bill & Melinda Gates Foundation — the world's largest private charitable foundation, which has helped save more than 80 million lives through vaccine and disease-eradication programs and is now spending down its entire endowment by 2045.
Bill Gates in 2025 at the European Commission, Brussels. Photo: Christophe Licoppe / European Union (CC BY 4.0).
From Harvard Dropout to Microsoft Co-Founder
Bill Gates co-founded Microsoft with his childhood friend Paul Allen in 1975, while Gates was a sophomore at Harvard. Their founding bet was that a computer would eventually sit on every desk and in every home — a genuinely radical idea at a time when computers were room-sized mainframes owned by corporations and universities, not individuals. Gates dropped out of Harvard to focus on the company full-time.
The IBM Deal That Built an Empire
The single most important business decision in Gates' career came in 1980, when IBM asked Microsoft to supply an operating system for its new personal computer. Microsoft didn't have one ready, so it purchased the rights to an existing operating system called 86-DOS for roughly $50,000, adapted it, and licensed it to IBM as PC-DOS while retaining the right to license the same software — renamed MS-DOS — to any other computer maker. That licensing structure, not the IBM deal itself, is what made Microsoft dominant: as IBM-compatible "clone" PCs from other manufacturers exploded in popularity through the 1980s, nearly every one of them shipped with Microsoft's software, and Microsoft collected a fee on each sale.
Windows, the IPO, and Becoming a Billionaire
Microsoft went public in 1986. The stock's rise made Gates a billionaire by 1987, at age 31, making him the youngest self-made billionaire in the world at the time. Windows, launched in 1985 and refined through the 1990s (particularly Windows 95), extended Microsoft's dominance from the command-line MS-DOS era into the graphical-interface era that defined mainstream computing for the next two decades.
18 Years as the World's Richest Person
Gates held the title of the world's richest person for 18 total years between 1995 and 2017, including a 13-year consecutive stretch. He became the first "centibillionaire" (net worth over $100 billion) in 1999 at the height of the dot-com boom. As of 2026, his net worth is estimated at roughly $105–108 billion, still placing him among the world's wealthiest individuals even after tens of billions of dollars in charitable giving.
Stepping Back From Microsoft
Gates stepped down as Microsoft's CEO in 2000, handing the role to Steve Ballmer, though he stayed on as chairman and chief software architect for several more years. He left his full-time role at Microsoft in 2008 to focus on philanthropy, and resigned from Microsoft's board entirely in 2020 to concentrate on the Gates Foundation, climate investing, and global health work.
The Gates Foundation: The Second Half of His Fame
Bill and Melinda Gates launched the Bill & Melinda Gates Foundation in 2000. It has since become the largest private charitable foundation in the world, with an endowment of roughly $92 billion as of mid-2026. Its work funding vaccine delivery, malaria treatment, and polio eradication campaigns — often through partnerships like Gavi, the Vaccine Alliance — has contributed to saving an estimated 80 million-plus lives and helped cut global child mortality in half. Malaria deaths alone have fallen by an estimated 12.7 million over 25 years due in significant part to this kind of coordinated funding.
In May 2025, Gates announced he intends to give away "virtually all" of his wealth and wind down the foundation entirely by 2045, projecting that roughly $200 billion will be distributed over that period — one of the largest philanthropic commitments ever made by a single individual.
| Era | What Gates Was Known For |
|---|---|
| 1975–1986 | Co-founding Microsoft, the MS-DOS/IBM licensing deal |
| 1986–2000 | Windows dominance, Microsoft IPO, world's richest person |
| 2000–2008 | Stepping back from CEO role, launching the Gates Foundation |
| 2008–2020 | Full-time philanthropy, global health and vaccine funding |
| 2020–2026 | Leaving Microsoft's board, pledging to spend down the foundation by 2045 |
FAQ
Why is Bill Gates famous?
Bill Gates is famous first as the co-founder of Microsoft, the software company whose MS-DOS and Windows operating systems made personal computers mainstream, and second as the co-founder of the Gates Foundation, the world's largest private charitable foundation, which has funded vaccine and disease-eradication programs credited with saving over 80 million lives.
How did Bill Gates become rich?
Gates became rich primarily through Microsoft's 1986 IPO and the company's subsequent growth, driven by licensing MS-DOS and later Windows to virtually every IBM-compatible PC manufacturer. He became a billionaire in 1987 and the world's richest person by 1995.
Is Bill Gates still the richest person in the world?
No. Gates was the world's richest person for a combined 18 years between 1995 and 2017, but as of 2026 his net worth of roughly $105–108 billion ranks him outside the top ten, behind figures like Elon Musk, due to both other fortunes growing faster and Gates' own large-scale charitable giving.
How much has Bill Gates given to charity?
Gates has donated tens of billions of dollars to the Gates Foundation over his lifetime and, as of 2025, has committed to giving away virtually all of his remaining wealth — an estimated $200 billion — by the time the foundation winds down in 2045.
What does the Gates Foundation actually do?
The Gates Foundation funds global health programs (vaccine delivery, malaria and polio eradication, maternal health) and development work aimed at reducing extreme poverty, largely by supporting partner organizations like Gavi, the Vaccine Alliance, and the WHO's polio eradication campaigns.
Is Bill Gates still involved with Microsoft?
Not operationally. Gates stepped down as CEO in 2000, left his full-time role in 2008, and resigned from Microsoft's board of directors in 2020. He holds no executive or board position at the company today.
Did Bill Gates invent MS-DOS?
No. Microsoft purchased the rights to an existing operating system, 86-DOS, from Seattle Computer Products for about $50,000 in 1980-81, then adapted and licensed it to IBM as PC-DOS and to other manufacturers as MS-DOS. Gates' key contribution was the licensing strategy, not writing the original code.
What is Bill Gates doing now, in 2026?
Gates spends most of his time on the Gates Foundation's global health and development work, climate-focused investing through Breakthrough Energy, and TerraPower, the nuclear power company he founded — while continuing to wind the foundation's endowment down toward its planned 2045 closure.
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