With the recent release of Windows Vista and Office 2007, Microsoft is expecting a wave of upgrades from users seeking the latest functionality. But not everyone is looking for new bells and whistles. Some folks want to keep their old operating systems running for as long as possible. That includes Windows 2000.

Microsoft isn't making it easy. Office 2007 and the software for the company's much-hyped Zune music player won't install on Windows 2000. As Microsoft puts out new products, fewer of them are likely to run on Windows 2000.

Are these installation restrictions caused by a real lack of capabilities in Windows 2000, or are they a Microsoft squeeze play to convince buyers that they must immediately upgrade their PCs to Vista and servers to Server 2003 or the forthcoming Longhorn Server? One product to look at is Microsoft's Windows Defender anti-spyware program. It can be downloaded for free but will install only on Windows XP, Server 2003, and higher. The application won't install on Windows 2000, according to Microsoft's documentation. But users report that this is simply an artificial rule built into the Installshield package that copies Defender files to disk.

The installer contains a condition defined as VersionNT > 500. (Windows 2000 is technically considered version 5.0 of Windows NT.) Administrators who have removed this condition using Orca, an Installshield editor, say Defender then installs and runs fine on Windows 2000. (Find out how to do this at support.microsoft.com/kb/255905.)

Regardless of whether Microsoft apps are unnecessarily shutting out Windows 2000, the writing is on the wall. The company has strict policies defining when it stops supporting older products. For Windows 2000, the end of Microsoft's "mainstream support" came in June 2005.

LIFE CYCLE APPROACH

To understand the concept of mainstream support, you need to understand Microsoft's three life cycle policies:

>> Consumer products, such as Windows XP and Service Pack 2, get five years of mainstream support. After that, support is provided only by Knowledge Base articles online.

>> Annually updated products, such as Microsoft Money and Encarta, get an even shorter leash. They're supported for three years.

>> Business software, such as Windows 2000 and Windows Server 2003, enjoy five years of mainstream support plus five years of "extended support," after which they drop into online-only support purgatory.