Microsoft has confirmed the existence of six separate Windows 7 versions. That's identical to what launched with Windows Vista, although you won't likely see Windows 7 Home Basic appearing on your local store shelves. Nor might you be able to use Windows 7 Starter, depending on where you live and the hardware you're intending to run it on.
Confused? Here's a full breakdown of Windows 7 shipped editions, ordered by complexity:
Windows 7 Starter
Available: Emerging markets only, only installed on OEM-specific machines and limited to certain kinds of hardware
*Ignores background applications like file backup utilities, but will trigger if you actually open up the backup program
Windows 7 Home Basic
Lacks: Aero enhancements, live thumbnail previews, Internet connection sharing
Available: Emerging markets only (no U.S., Western Europe, Japan, and other developed countries)
Windows 7 Home Premium
Includes: Aero enhancements, multitouch capability, media functionality for playing movies and burning DVDs, and the ability to create home network groups
Windows 7 Professional
Windows 7 Enterprise
Available: Volume licensing only
Windows 7 Ultimate
Includes: Everything. The whole enchilada. Just not any Ultimate extras--Microsoft has scrapped the notion of these extended add-ons for its future operating systems.
Available: Limited availability
What to Get and How to Install It
Microsoft intends for Windows 7 Home Premium and Windows 7 Professional to be the two editions that most consumers are apt to pick up. Your Average Joe should target the former, whereas small business-themed customers will want to opt for the latter. Microsoft has yet to offer its official suggestions for or hardware recommendations for the operating systems, so stay tuned. However, Microsoft alleges that the various editions of Windows 7 will be able to run on a "very broad set of hardware, from small-notebook PCs (sometimes referred to as netbooks) to full gaming desktops."
Microsoft has yet to announce price points for any of the Windows 7 products. Upgrading from a lesser Windows 7 version to a more meaty variety will be handled through Microsoft's electronic upgrade capabilities. Going from a standard Vista Home Basic or Home Premium install to Windows 7 won't require a reformat of any kind. According to Windows guru Paul Thurrott, the new operating system can be installed right overtop of these Vista editions without complications. Going from XP to Windows 7 will require a clean installation, as will jumping from a 32-bit Windows 7 installation to a 64-bit installation.