Microsoft rolled out Windows Vista at retailers in 70 countries today.
The world's biggest software maker marked the launch of its first all-new Windows operating system in five years with a marketing blitz including commercials featuring basketball star Lebron James and appearances by Bill Gates.
"We have just begun to see what we can do," Mr Gates said at an event in London. "We will be taking entertainment to a whole new level . . . even education we believe will be changed very dramatically."
Vista, which required a $6 billion investment from Microsoft, will be installed on more than 100 million PCs worldwide, according to research reports.
Windows runs on more than 95 per cent of the world's computers and the long-delayed new version is the first major release of a new Microsoft operating system since it introduced Windows XP in 2001.
In his speech at the British Library, Mr Gates proclaimed that Vista's capabilities would be used to put online Leonardo da Vinci's famous Codex Arundeland Codex Leicesternotebooks, making available the artist's drawings, mirror writing and theories to the public.
The Codex Arundelis held at the library, while Gates owns the Codex Leicesterafter he paid $30 million for the manuscript in 1994.