Proclaiming himself "humbled and delighted," Microsoft founder Bill Gates received the accolade from Queen Elizabeth II in a private ceremony at Buckingham Palace.

As an American, Gates is not entitled to use "Sir" before his name, but he can put the initials "K.B.E." - Knight Commander of the British Empire - after it.

The 49-year-old billionaire was honored for his charitable activities around the world and his contribution to high-tech enterprise in Britain.

Past recipients of the honorary knighthood range from Irish singer Bob Geldof to former President Ronald Reagan.

"This honor is particularly poignant given the deep connections Microsoft enjoys with the United Kingdom," said Gates, whose company employs about 2,000 people in Britain. Gates has an estimated wealth of $48 billion.

Gates' honor - bestowed by the queen on the advice of the government - was announced in January 2004, but a "mutually convenient" date to receive it had not been available until now.

British recipients of knighthoods are entitled to be addressed with a "Sir" before their names. The honor was long the preserve of senior soldiers, judges and other servants of the state, but recent years have seen the creation of Sir Paul McCartney, Sir Mick Jagger and Sir Elton John.

"It's a great honor to have the association with this country and receive an award like this," Gates said as he and his wife, Melinda, stood under black umbrellas outside the palace, holding his silver medallion in a small black box with velvet lining.

His wife described the queen as "engaging" company and said they had found plenty to talk about on issues such as health problems in the developing world, the avian flu and their shared interest in travel.

But on the subject of computers, it seems the monarch does not enjoy the same passion for technology as Gates.

"She said all the kids do (use computers), and the computer helps to schedule things. But she said for she herself ... typing is not as natural for her as it is for young people," Gates said.

He joins a roster of American honorary knights that includes former presidents Reagan and George H.W. Bush, comedian Bob Hope, retired U.S. Army Gen. Tommy Franks and former Secretary of State Colin Powell.

Gates said he was proud of what he called Microsoft's "special relationship" with Britain.

"The U.K. was the first country in which Microsoft set up a subsidiary outside the U.S., and our experience in the U.K. has been significant in shaping our international growth," he said.

Microsoft's British facilities include Research Cambridge, a laboratory established in 1997 in the university town that employs 80 scientists. In 2000, the Bill & Melinda Gates Foundation announced a donation of $210 million to Cambridge University to create a scholarship program for graduate students from outside Britain.