On Friday, Microsoft revealed details about two alternative ways to purchase Windows 7: Windows Anytime Upgrade (WAU) and the Windows Family Pack. As has been the case with all the software giant's Windows 7 pricing announcements, however, there's bad news mixed in with the good.

Microsoft originally created WAU for Windows Vista, and in the original version of the service, customers could electronically upgrade from some Vista product editions (e.g., Vista Home Basic) to others (e.g., Vista Home Premium). The problem, however, was that Vista customers using WAU needed their original Vista Setup disc to perform the upgrade. So after months of complaints, Microsoft dropped the electronic-upgrade option, requiring users to purchase WAU retail packages—which included setup discs—instead.

With Windows 7, WAU once again has an electronic option. The difference this time around is that no setup disc is required: All the software code necessary to perform any upgrade via WAU is already installed on the hard drive. WAU pricing is typically somewhat less than similar upgrade options in Vista, as well (depending on which product edition is being upgraded to which product edition.) In the United States, the prices break down as follows:

Windows 7 Starter to Home Premium: $79.99
Windows 7 Starter to Professional: $114.99
Windows 7 Starter to Ultimate: $164.99
Windows 7 Home Premium to Professional: $89.99
Windows 7 Home Premium to Ultimate: $139.99
Windows 7 Professional to Ultimate: $129.99

These prices are typically less expensive than a full Windows 7 Upgrade package. For example, Windows 7 Home Premium typically costs about $99.99, $20 more than the WAU Starter to Home Premium offering.

With regards to the Windows 7 Family Pack, Microsoft curiously revealed that it was making such a product almost two weeks ago but declined at the time to specify pricing or which markets in which the Family Pack would be offered. The news here isn't good.

The Windows 7 Family Pack provides a setup disc and three product keys for Windows 7 Home Premium, providing you with the ability to legally install the product on three PCs. It will cost just $149.99 in the United States (C$199.99 in Canada)—a significant savings over three Windows 7 Home Premium Upgrade boxes. But here's where the catch comes: Microsoft says it's offering the Family Pack only "while supplies last." That's right, it's a temporary offer.

It gets worse. The Windows 7 Family Pack won't be offered at all in many markets, and in some others—like Europe—there apparently won't be a Family Pack offer until 2010. I haven't been able to confirm the full country listing for Family Pack as of this writing.

I wrote the first detailed overview of WAU for Windows 7 in February and just updated it with screenshots from the final version. You can check that out on the SuperSite for Windows.