Consumers will be able to buy the much-delayed Vista and the final version of Microsoft's Office 2007 business applications software from January 30.

By then, Microsoft hopes, major business customers will have signed on in droves to show the capabilities of the successor to the Windows XP operating system for personal computers.

Microsoft chief executive Steve Ballmer said the company expected to attract over 200 million users worldwide of Vista and its attendant software tools by the end of next year.

"During the last decade, Windows 95 and Office 95 transformed the way people work," he said in remarks prepared for a glitzy press launch in New York's Times Square.

"These new products announced today are the most advanced work that Microsoft has ever done, and I believe they signal the beginning of a new wave of innovation that will have an even more profound impact during the next decade," he said.

It has been five years since Microsoft introduced Windows XP. The Windows system is used by approximately 90 percent of the world's PCs with 70 percent of the machines running on XP.

Vista features that promise to be of particular interest to businesses include BitLocker, which encrypts data stored on computer hard drives, according to Michael Cherry of independent consultancy Directions on Microsoft.

"If the drive is lost or stolen, you've lost your hardware but no one can read the data," Cherry said of BitLocker, which was in Vista for enterprise servers and the premium Vista version for PCs.

"Those embarrassing stories we read in the news should be reduced," he said.

Corporate clients may be averse to becoming "early adopters" until Microsoft has had time to iron out any glitches in the new operating system, analysts believe.

But Microsoft insists that it has worked overtime to eliminate bugs, having worked with hundreds of thousands of software partners, companies and experts in the lengthy development of Vista.

According to a Capgemini study commissioned by Microsoft, early adopters expect "dramatic gains" in their productivity through using Vista and software such as the new Exchange Server 2007 platform.

Ballmer said the new suite of Vista products could generate more than 250 billion dollars in extra revenues for companies through making their computing lives easier.

"No set of product releases in history has ever offered this level of opportunity for the industry as a whole," he said.

Microsoft is touting Vista's increased security over XP, and the ability it gives corporate IT officers to control large banks of desktops computers centrally.

Exchange Server 2007 will streamline companies' in-house and external communications, the company says, while in-built search technologies will help users to find information more easily.

And Microsoft has taken a leaf from its rival Apple Computer in incorporating "Aero" transparency software into Vista that enables users to see through a page to view what is beneath it on the screen.

However, the launch delays are believed to have hurt holiday-season PC sales because shoppers could be averse to buying computers with operating systems that are soon to be obsolete.

Microsoft has tried to mitigate damage to end-of-year sales by offering buyers coupons for free or low-cost upgrades from Windows XP to Vista.