Some previous reports said Windows Vista's adoption would be rather slow but now an analyst predicts Windows Vista's adoption will be faster than Windows XP's. David Mitchell, software practice leader at Ovum, says up to 15 percent of PC users will switch to Windows Vista within the first year that the operating system is available.

By comparison, between 12 to 14 percent 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.