Microsoft has unveiled six variants of its upcoming Windows Vista operating system targeted at businesses and consumers, including a starter pack for emerging markets.

Scheduled for release in the second half of this year, the Windows Vista product lineup comprises two versions for businesses, three for consumers and one for emerging markets. They are: Windows Vista Business, Windows Vista Enterprise, Windows Vista Home Basic, Windows Vista Home Premium, Windows Vista Ultimate and Windows Vista Starter.

The number of offerings is the same as the ones currently available for Windows XP.

ZDNet Asia's sister site, Silicon.com, last week reported that Microsoft posted the names of the six core and two other non-Media Player versions on its Web site but took down the information shortly after.

According to Microsoft, each product is tailored for home PC users, small and medium-sized businesses and large enterprises. The lineup is also aimed at bringing 64-bit Media Center and Tablet PC functionality into the mainstream.

Business customers can choose from two versions: Windows Vista Business and Windows Vista Enterprise.

Designed for organizations of all sizes, Windows Vista Business comes with a new user interface called Windows Aero which touts desktop navigation improvements and smoother business document management.

In addition, Windows Vista Business will come with Windows Tablet PC technology, which provides built-in handwriting recognition and enables interaction with the PC via a digital pen or fingertip instead of a keyboard.

Windows Vista Enterprise will come with all of the features available in Windows Vista Business. In addition, it will provide higher levels of data protection using hardware-based encryption technology.

For home users, Windows Vista is available in two flavors: basic and premium. In addition to basic functions such as Internet browsing, e-mail or document creation, Windows Vista Home Basic will provide new tools such as a Search Explorer, Sidebar and Parental Controls.

Windows Vista Home Premium will come with the new user interface Windows Aero, an integrated search function, Windows Media Center capabilities, Windows PC Tablet technology and integrated DVD burning and authoring.

According to Microsoft, Windows Vista Ultimate is the first operating system that brings together all the entertainment features, mobility features and business-oriented features available in Windows Vista.

All new versions are available for either 32-bit or 64-bit systems, except for Windows Vista Starter, which is available only for 32-bit systems.

Windows Vista Home Basic, Home Premium, Ultimate and Business will be available as a full-packaged product at retail and on new PCs. Windows Vista Enterprise will be offered only to business customers participating in Microsoft’s Software Assurance program.

Microsoft will offer Windows Vista Starter in emerging markets.

Al Gillen, research director for System Software at IDC said: "Windows Vista is going to be a significant release for all Windows customers--including enterprises, small and medium-sized businesses as well as consumers.

"Microsoft’s strategy to address different customer segments with versions of Windows Vista optimized for their needs should be well received by these diverse user segments."