Microsoft has revealed its sweeping plan to get Windows Vista Release Candidate 1 (RC1) into the hands of millions of new testers and released final pricing for the operating system.

The public test of RC1 will involve more than five million users and will dramatically increase the availability of Windows Vista to millions of new users - more than doubling the size of its initial Beta 2 Customer Preview Program (CPP). That program involved 1.5 million users.

RC1, which was made available to a small number of technical beta testers on Friday, will be made available to the 1.5 million CPP participants this week. After the release candidate has been made available to existing CPP participants, the program will be opened to new users. In addition, RC1 will be posted to MSDN and TechNet, where subscribers can download it. Microsoft will also include cover mounts of RC1 on magazines worldwide.

The widespread testing of RC1 is being done to help Microsoft meet its January 2007 deadline for getting Windows Vista into the hands of consumers, and November 2006 deadline for getting it into the hands of volume licence customers. Having millions of new users test the operating system will help Microsoft track down bugs, and ensure that Vista works with as wide a range of hardware as possible.

RC1 will work until 31 May 2007, after which it will time out. Microsoft will issue updates and patches to RC1 until it is released to manufacturing, at which time the operating system is considered finished, and the manufacturing and distribution process will begin.

Pricing for Vista

Microsoft said Windows Vista Home Basic will have a suggested retail price for the full packaged product of $199, with a suggested upgrade retail price of $99.95. Home Basic does not include a number of Vista features, such as the Aero interface.

Windows Vista Home Premium will have a suggested retail price for the full packaged product of $239, with a suggested upgrade retail price of $159. Windows Vista Business, which includes a variety of tools and features for businesses, will have a suggested retail price for the full packaged product of $299, with a suggested upgrade retail price of $199.

And Windows Vista Ultimate, which includes all the major features of Windows Vista Business and Windows Vista Home Premium, will have a suggested retail price for the full packaged product of $399. The suggested upgrade retail price for this version of Vista will be $259.

Microsoft has not yet announced volume pricing for Windows Vista Enterprise.

Changes in RC1

Microsoft has made numerous changes to Windows Vista with the release of RC1. It has reworked the Network and Sharing Center to make it easier to use, improved Internet Explorer and reworked the Parental Control feature.

The User Account Control security feature, which has been criticised by beta testers because of its intrusiveness, has been significantly streamlined and presents far fewer prompts. In addition, overall performance improvements have been made possible by fine-tuning I/O of background services.

Microsoft also said it has substantially enlarged the driver pack to make it work better with a wider range of components and peripherals.

Windows Vista application programming interfaces are locked with RC1 and will not change, so developers can begin writing Windows Vista-specific applications and utilities knowing that they will work on the shipping product, according to Microsoft.