Windows Vista is finally on its way to manufacturers, the software giant has announced.

The frequently delayed update to Windows XP will be available to consumers on 30 January, Microsoft confirmed - the date online retailer Amazon.com had posted in August for pre-orders.

"This is a good day," said Jim Allchin, co-president of Microsoft's Platform & Services Division. "Vista is rock solid and we're ready to ship." The most recent release to manufacturers (RTM) date was recently pushed back from 25 October to 8 November because a last-minute bug.

Once Vista is in the hands of manufacturers, hardware vendors can begin installing it and configuring it on computers that will be sold via retail channels beginning in January 2007. Microsoft also plans to have Vista in the hands of business customers by the end of November, and is hosting a launch event in New York on 30 November to mark the occasion. At the same time the company will also launch Office 2007 and Exchange Server 2007.

Allchin said he expects business customers will jointly deploy all three of those products, which will give them "dramatic benefits" in security and reliability. He cited security as a primary reason for both consumers and businesses to upgrade and said Microsoft had paid closer attention to security in Vista than it ever has in any other Windows OS.

"In my opinion, it's the most secure system that’s available and the most secure system we have shipped," he said. This means the number and severity of security updates Microsoft must release every month on Patch Tuesday, the name security researchers have given for when Microsoft releases its monthly security patches, should be reduced.

Vista has been a long time in the making, and was originally scheduled to hit retail channels this month in time for the busy holiday shopping season. Microsoft is offering coupons through its hardware channel to encourage customers to buy Vista-ready PCs during that time so they can upgrade to Vista when it's available generally.

Business customers have said they likely will not upgrade to Vista immediately after its release, but will probably wait until a first service pack for Vista is available.