Microsoft has announced the consumer version of its new Windows Vista operating system (OS) will be available to retail customers from 30 January 2007.

New features of the OS include claimed improvements to security, a 3D interface as well as more search options. Office 2007 will also be launched to consumers on that day.

Vista will be Microsoft's first new version of Windows for the PC market since 2001. The company said it expects its release to spark a rise of at least 10 per cent in sales of Windows PC software over the coming year.

The OS was released to manufacturers yesterday. But because the release to retailers just misses the Christmas holiday period, to generate interest in the new system, a number of companies, such as PC World are offering people free upgrades to Vista if they buy a new PC with the older Windows XP installed now.

Microsoft is also offering coupons for free or discounted versions of Vista for these PCs.