Bill Gates launched Windows Vista and Office 2007 in London today at the end of a round-the-world event that put the software into 70 countries and 19 languages.

Gates was at the British Library, which is working with Microsoft to digitise parts of its vast collection, to push the operating system that has Microsoft a global giant. He handed over his own personal copy of a Leonardo da Vinci book to be scanned.

He recalled how far the company had come since 1995, the year when a 32-bit Windows was launched. The idea was that Vista was a milestone for the company, but also a key element for the future of video and photos, e-commerce and VoIP. "Today is a big day and is really the start of something different," the richest man in the world told those there.

In Paris, it was a more jazzy affair with Microsoft flooding business district La Defense with Vista-liveried Smart cars and Segways.

Gates touched on the revamp of the Microsoft Office productivity suite, saying its new interface "only takes a few hours to learn". While Microsoft has said that Office 2007's new "ribbon" menu, which replaces the drop-down menus and toolbars, should make it easier to find certain functions, some users have said it is tricky to adapt to.

After Gates' initial presentation, he shared the stage with British Library chief exec Lynne Brindley to discuss the software application Turning the Pages 2.0, which the British Library uses to scan and compile downloadable renditions of texts in its collection.

Gates also had an item from his personal collection scanned - the Codex Leicester, one of only a few existing notebooks belonging to the artist and scientist Leonardo da Vinci. The British Library holds the Codex Arundel and both are now on the British Library's website.