Microsoft on Monday filled in one of the key pieces of its plan to sell Windows 7 to consumers and businesses: A decidedly simpler product lineup than that offered by its predecessor, Windows Vista. While the software giant will in fact offer several different Windows 7 product editions, or SKUs, to the public, only two of them will be broadly available to customers. Even more important, perhaps: Each product edition will be a true superset of one another, making it easier than ever for customers to pick the version that's right for them.

"As customers upgrade from one version to the next, they keep all features and functionality from the previous edition," Microsoft general manager Mike Ybarra says. "With Windows 7 there is a more natural progression from one edition to the next."

That wasn't the case with Windows Vista, where the consumer-oriented Home Premium edition included some features that were not available in the corporate-oriented Business edition, and vice versa. Now, as users step up through the product line-up, each version simply builds off the last, and no functionality is lost.

Regarding the actual product editions, Microsoft will offer two editions, Windows 7 Home Premium and Windows 7 Business, to mass markets in developed nations via retail outlets and with new PCs. Microsoft expects these two editions to meet most customers' needs. (A third Windows 7 Enterprise edition will be offered via volume licensing to businesses with Software Assurance subscriptions.)

A few other niche market versions will be sold as well. A limited Starter Edition will be offered worldwide, but only with new PCs. Windows 7 Ultimate will be functionally identical to Windows 7 Enterprise but will be offered to consumers who literally want every single Windows 7 feature. And a Home Basic version will be offered to emerging markets. Microsoft also confirmed that it will create a single "N" version of Windows 7 to meet its legal requirements in Europe; as before, however, few customers are expected to ever purchase this version as it does not include Windows Media functionality.

Because each product edition is a superset of the one before it, each builds off of the functionality of the lower-end edition. Listed in order of functionality, the Windows 7 product lineup breaks down like so: Starter, Home Basic, Home Premium, Professional, Enterprise/Ultimate. One of the benefits of this approach is that a product like Windows 7 Professional now includes the full digital media suite of applications that also appears in Windows 7 Home Premium.

Despite the simplification of the lineup, some still feel that Microsoft is artificially bifurcating Windows in order to pump up profits. The company says that isn't the case. "Within a customer base of over one billion, there are a lot of important customer niches, or segments, and we want to make sure we have an appropriate product for everybody," Ybarra noted. "We understand some of our customers have different needs, like enthusiasts who want every feature in Windows, for example. But for a majority of our customers the choice is really simple: Windows 7 Home Premium or Windows 7 Professional."

Microsoft also ended speculation that it would create a version of Windows 7 designed specifically for low-end netbook computers. Instead, the company will let PC makers choose which versions to put on their machines; Windows 7 is speedy enough to run well on that class of hardware regardless of which version is used, the company says.

One important bit of information is still to come: Pricing. How Microsoft prices retail boxed copies of the OS, PC bundles, and upgrades will in large part determine how quickly this new Windows version takes off. Microsoft is expected to release its pricing and licensing plans in the coming weeks.

For more information about the Windows 7 product edition lineup, including a feature breakdown for each edition and other details about upgrading, please refer to my article on the SuperSite for Windows.