The way people interact with computers is going to dramatically change in the next five years, Microsoft chief Bill Gates has told BBC News.
He predicted that the keyboard and mouse would gradually give way to more intuitive and natural technologies.
In particular, he said, touch, vision and speech interfaces would become increasingly important.
Mr Gates made his comments whilst answering questions from BBC News website readers.
"This whole idea of what I call natural user interface is really redefining the experience," he said.
"We're adding the ability to touch and directly manipulate, we're adding vision so the computer can see what you're doing, we're adding the pen, we're adding speech," he told BBC News.
During the interview Mr Gates showed off the Microsoft Surface computer, a large table like machine with a multi-touch interface.
"I'll be brave, in five years we'll have many tens of million of people sitting browsing their photos, browsing their music, organising their lives using this type of touch interface," he said.
Mr Gates expanded on this theme of natural interfaces during the CES keynote speech he made on the first day of the hi-tech fair.
Citing the success of the iPhone and the controller for the Nintendo Wii game console, Mr Gates said such interfaces were a big hit with consumers.
Although Microsoft Windows has become the most widely used operating system in the world, Mr Gates admitted, in answer to readers questions, that he had not always got things right.
"People thought we were late with the [web] browser," he admitted.
In addition, he said, search was an area where people thought that Microsoft had not fulfilled expectations.
"Google has done a good job," he said. "We expect to surprise people that we can match and even do better there - people should wait and see."
Mr Gates also answered questions about Windows Vista, the firm's often-criticised operating system, launched last year.
"I'm very proud of Vista," he said. "Like all of the products we ship, we hear how we could do this differently or that differently."
He said the firm had received "lots of feedback" on the software.
"We do downloads and improvements all of the time and of course there'll be a major new version coming along," he said.
Microsoft has just announced that it has sold 100 million licences for the operating system.
During the questions and answer session he also revealed his own computer habits.
"There are a lot of PCs in my house - over 10," he said.
In particular, he said, he used a tablet PC, a notebook computer that is operated with a digital stylus.
However, he said, he does not use his competitor's products.
"There are no Macs in my house," he admitted.