Bill Gates, born in Seattle in 1955, co-founded Microsoft with his school friend Paul Allen in 1975. Microsoft’s MS-DOS and Windows software ran on computers around the world. Gates stepped down as Microsoft’s boss in 2000 and now leads the Gates Foundation, which works on vaccines, polio and poverty and plans to close by the end of 2045.
Bill Gates quick facts
- Bill Gates co-founded Microsoft with Paul Allen in 1975.
- Microsoft’s first sale was a version of BASIC for the Altair computer.
- Windows went on sale on 20 November 1985.
- Gates stepped down as Microsoft’s CEO in 2000.
- The Gates Foundation plans to close at the end of 2045.
Who is Bill Gates?
Bill Gates is an American businessman who co-founded the computer software company Microsoft with his school friend Paul Allen in 1975. Microsoft’s programs have run on computers all over the world.
Later, Gates turned his attention to giving money away. The foundation he started with Melinda French Gates, now called the Gates Foundation, works to improve health and fight poverty around the world.
In 2025, he announced that the foundation would spend its money and close by the end of 2045.
| Bill Gates at a glance | |
|---|---|
| Full name | William Henry Gates III |
| Born | 1955, Seattle, Washington, USA |
| Co-founded | Microsoft, in 1975, with Paul Allen |
| Microsoft boss (CEO) | until 2000 |
| Charity | the Gates Foundation, begun in 1994 |
| Foundation plan | to close at the end of 2045 |
Growing up in Seattle
William Henry Gates III was born in Seattle, Washington, in 1955, the Harvard Gazette says.
The Gates Foundation says his father, William H. Gates Sr., was a lawyer and community leader. His mother, Mary Gates, was a schoolteacher who later helped lead the University of Washington and a charity called United Way International.
Bill went to Lakeside School, a private school in Seattle. In a 2005 speech published by the Gates Foundation, he explained that the school’s Mothers Club paid for a teletype machine, which connected to a faraway computer over the telephone line.
He started experimenting with that computer when he was about 13. He later wrote a program to make the school’s class timetable, and joked that he set it up so he had no lessons on Fridays.
At Lakeside, he met Paul Allen, who became his business partner. The Harvard Gazette says Gates started at Harvard University in 1973, but left in his third year to start Microsoft.
Starting Microsoft
In January 1975, a new home computer called the Altair 8800 appeared on the cover of a magazine called Popular Electronics. Microsoft says it inspired Allen and Gates.
According to Microsoft’s history, on 1 February 1975 they finished a version of the BASIC programming language for the Altair, and sold it to their first customer, a company called MITS in Albuquerque, New Mexico.
Microsoft says Gates was 19 and Allen was 22 when they sold their first program. It says this was the first computer language program for a personal computer.
On 29 July 1975, Gates wrote “Micro-soft” in a letter to Allen, the earliest known use of the name. Microsoft says it joins the words “microprocessors” and “software”.
It started small. Microsoft says the company’s sales for all of 1975 came to just $16,005.
MS-DOS and Windows
Microsoft’s big break came in 1981. On 12 August that year, the computer company IBM launched its Personal Computer, running Microsoft’s MS-DOS 1.0.
MS-DOS was an operating system, the software that runs a computer and lets other programs work. Microsoft says it was the company’s first step into operating systems.
On 20 November 1985, Microsoft began selling Windows in shops, adding pictures and windows on top of MS-DOS. By its 10th birthday in 1985, Microsoft says, its sales for the year had reached $140 million.
In 1986, Microsoft moved its headquarters to Redmond, near Seattle. By the late 1980s, it was the world’s biggest personal-computer software company. By June 2026, Microsoft says, it had about 223,000 employees around the world.
Stepping back from Microsoft
Gates ran Microsoft as its chief executive, or CEO, until 2000, when Steve Ballmer took over. Microsoft says Gates then became chief software architect, in charge of its technology plans.
In June 2006, Microsoft announced that Gates would stop working there day to day, to spend more time on his foundation’s health and education work. His day-to-day role ended on 27 June 2008.
He stayed chairman of Microsoft’s board until 2014. On 13 March 2020, Microsoft says, he left the board to focus on global health, development, education and climate change.
The Gates Foundation
The Gates Foundation says it grew out of the William H. Gates Foundation, started in 1994, and became the Bill & Melinda Gates Foundation in 2000. Melinda French Gates stepped down as co-chair in 2024, and Bill Gates is now the foundation’s chair.
It is one of the biggest charities in the world. The foundation says that by the end of 2025, it had given out $110.9 billion since it began, including $8.47 billion in 2025 alone.
Other people have given it money too. The foundation says the investor Warren Buffett gave it $47.9 billion between 2006 and 2025.
In 2025, the foundation says, it paid for work in 143 countries. Its headquarters is in Seattle, and it has 2,215 employees.
Vaccines and polio
Much of the foundation’s work is about health. It says that in 2000 it helped create Gavi, an alliance that helps children in poorer countries get vaccines, with a promise of $750 million for its first five years.
Polio is a disease that can paralyse children. The Gates Foundation says that in 1988, polio paralysed about 1,000 children every day in more than 125 countries. Since then, cases have fallen by 99%.
The foundation estimates that about 20 million children have been saved from paralysis. It says wild polio is now found only in Afghanistan and Pakistan, and nearly 370 million children are vaccinated against it every year.
Giving it all away by 2045
On 8 May 2025, Bill Gates announced that the foundation would spend $200 billion over 20 years and then close at the end of 2045. He said he would “give away virtually all my wealth” through the foundation.
The foundation says it has three goals for 2045: that no mother or baby dies of a preventable cause, that children grow up free of deadly infectious diseases, and that hundreds of millions of people escape poverty.
In January 2026, it approved a yearly budget of $9 billion, with about 70% going to global health. Its 2026 letter warned that 2025 was almost certainly the first year this century in which more children died than the year before.
Books and other work
Gates has written several books. Penguin Random House, his publisher, lists titles including The Road Ahead, How to Avoid a Climate Disaster and How to Prevent the Next Pandemic.
How to Avoid a Climate Disaster came out on 16 February 2021. It sets out a plan for cutting the gases that warm the planet down to zero. His memoir about growing up, Source Code, came out on 4 February 2025.
He also writes a blog called Gates Notes. Penguin Random House says he founded Breakthrough Energy, which backs clean-energy inventions, and TerraPower, which works on new kinds of nuclear power.
He never finished his degree, but in 2007, more than 30 years after leaving, he gave the main speech at Harvard’s graduation ceremony, the Harvard Gazette says.
Close to wiping out polio
The fight against polio is one of the foundation’s biggest projects. The Gates Foundation says it became a core partner of the Global Polio Eradication Initiative in 2007.
There has been real progress. The foundation says one type of wild polio, type 2, was declared wiped out in 2015, and type 3 in 2019. In 2020, the World Health Organization’s African region was declared free of wild polio.
A newer oral vaccine is helping too. The foundation says nearly 2 billion doses of this vaccine, called nOPV2, have been given.
Vaccines matter to the foundation because they save so many lives. It says that by 2020, it had given $6 billion to Gavi, the vaccine alliance, its largest single investment.
The foundation in numbers
The Gates Foundation says that from its start until the end of 2025, Bill Gates and Melinda French Gates together gave it $63.9 billion.
It says its endowment, the money it keeps and invests, was $89 billion at the end of 2025. In 2025 it paid for work in 143 countries, as well as in 45 US states and Washington, DC.
It also works on education. The foundation says that in 2017, it promised to spend $1.7 billion over five years on schools in the United States.
The foundation says Bill Gates has three children and two grandchildren.
More about Bill Gates
Microsoft grew fast after becoming a company. Microsoft says it was incorporated on 25 June 1981, with Gates as president and chairman and Paul Allen as executive vice president. That year, its sales reached more than $17 million.
Gates stayed chairman of Microsoft’s board until 4 February 2014, the day Satya Nadella became chief executive. After leaving the board in 2020, Microsoft says, he stayed on as a technology adviser.
His memoir, Source Code, tells the story of his early life. Penguin Random House says it covers his childhood, his parents and grandmother, his school days at Lakeside, Harvard and leaving college to start Microsoft.
He has been honoured in other countries too. The Harvard Gazette says he received an honorary British knighthood in 2005.
Three things people get wrong
Bill Gates did not start Microsoft on his own. He co-founded it with his school friend Paul Allen.
Microsoft did not start in Seattle. Its first customer was in Albuquerque, and it moved near Seattle later.
Bill Gates does not run Microsoft today. He stopped being CEO in 2000 and left its board in 2020.
Did you know? Microsoft’s total sales for its first year, 1975, were just $16,005.
Try it
Design a timetable for your ideal school week, like the young Bill Gates did for his school. Would you give yourself Fridays off?
Knowledge check
Who started Microsoft with Bill Gates?
Show answer
Paul Allen, his school friend.
What is an operating system?
Show answer
The software that runs a computer and lets other programs work.
Frequently asked questions
Why is Bill Gates famous?
He co-founded Microsoft, which made MS-DOS and Windows, and later started one of the world’s biggest charities, the Gates Foundation.
When did Bill Gates start Microsoft?
In 1975, with his school friend Paul Allen. Their first sale was a version of the BASIC language for the Altair computer.
Does Bill Gates still run Microsoft?
No. He stopped being CEO in 2000, stopped working there day to day in 2008 and left its board in 2020.
What does the Gates Foundation do?
It funds work on health, vaccines, polio, education and fighting poverty. In 2025 it paid for work in 143 countries.
When will the Gates Foundation close?
Bill Gates announced in May 2025 that it will spend $200 billion over 20 years and close at the end of 2045.
What books has Bill Gates written?
His books include The Road Ahead, How to Avoid a Climate Disaster, How to Prevent the Next Pandemic and Source Code.
Sources
- Gates Foundation: our story — the foundation’s history, Gavi, polio, Warren Buffett and education; its fact sheet, leadership, polio pages and 2005 Lakeside speech were also used
- Gates Foundation: 25th anniversary announcement (May 2025) — the $200 billion plan and closing in 2045; its January and February 2026 announcements were also used
- Microsoft: history of Microsoft, 1975 — the Altair, BASIC, the first sale and the name; Microsoft’s 1981 and 1985 history pages were also used
- Microsoft: change to its board of directors (2020) — Gates leaving the board; Microsoft’s 2006 announcement and facts page were also used
- Harvard Gazette: Bill Gates to speak at Commencement (2007) — his birth, Harvard years and the 2007 speech
- Penguin Random House: Bill Gates — his books and energy companies; its pages on Source Code and How to Avoid a Climate Disaster were also used
