It promised that it will deliver a better experience for users when it arrives sometime late next year.
Among the new features promised in the latest operating system are Windows Touch, which introduces support for multi-touch technology. This will enable users to zoom in on an image by moving two fingers farther apart - a technology first introduced to millions of users by Apple's iPhone.
A new taskbar aims to give more rapid access to files and programs, with each open window appearing as a graphic thumbnail.
There is also a feature called HomeGroup, allowing users easy sharing of data across PCs and other devices in the home.
And there is more support for devices such as cameras, printers, and mobile phones with a product called Device Stage offering a single window to manage tasks for each device.
Microsoft's chief software architect Ray Ozzie indicated that Windows 7 would be evolutionary rather than revolutionary. "Vista is a great operating system, it's tremendously functional," he told the BBC. "Windows 7 brings it up a level by enabling it to take advantage of certain hardware innovations. PCs have evolved since Vista was launched," he said.
Microsoft also announced that its Office software will now be available as a web application, so that users can create and share documents across multiple devices. Microsoft's Office Web will be supplied to customers who purchase the next edition of Office, but Microsoft stressed that it will provide all the same functions online as are available offline.
The new operating system is scheduled for release in 2010 and the advance code still had limited functionality. A widely released public trial, or beta, version is expected to be available in early 2009.
