Adoption of Microsoft's Windows Vista operating system will happen at a faster pace than any previous operating system release, a software analyst predicted last week.

Up to 15 per cent of PC users will move to Vista within the first year that the operating system is available, said David Mitchell, the software practice leader at Ovum. "That would make it the fastest-moving operating system ever," he said.

By comparison, between 12 to 14 per cent of users switched to Windows XP during the first year of its release, Mitchell said.

Vista gain traction in the market from quick adoption by both corporate and consumer users. For example, companies that participate in Microsoft's Software Assurance licensing program will automatically get upgrades to Vista, Mitchell said. "On the consumer side, there has been a bit of pent-up demand. Just look at the beta adoption in the consumer space -- it's very high," he said.

Vista will be available to business customers from November 30, with the operating system available to consumers from January. For users who buy a new computer before Vista is released to consumers, Microsoft is now shipping Vista upgrade coupons with computers that are sold with Windows XP.

The upgrade coupons mean that Microsoft will not be hurt financially by missing the year-end holiday shopping season -- a peak time for computer sales.

While corporate and consumer users will quickly move to Vista, the adoption prospects for Office 2007 -- which goes on sale at the same time -- are less clear. While many users may now see no need to upgrade, once Office 2007 starts to make its way into companies users may find themselves upgrading to keep pace, Mitchell said.

Overall, the rate of adoption of Office 2007 will be lower than Vista during the first year, Mitchell said. "You don't get the OEM drag effect. If you buy a new PC, you get a copy of Vista. You don't necessarily get a copy of Office," he said.