The latest Microsoft software that will stop receiving support from the company includes Windows 98, 98 Second Edition and Millennium. While these desktop operating systems may indeed appear to be ancient, Windows 98 represented 5% of the corporate Windows installed base at the end of 2005, according to IDC.

Other than operating systems, the Windows XP Service Pack 1 will also be retired for good on Oct. 10, and users are being advised to start planning now for completing upgrades to XP Service Pack 2, which has been much talked about for its security improvements.

The fact that the company has previously extended expiry dates, most notably for Windows NT and Exchange 5.5, users need to be aware that extensions are not the norm.

In January, the 5-year-old versions of connectors for BizTalk, Content Management Server, line-of-business applications, gateways for mainframe integration and Office programs for the Macintosh will all see the end of what Microsoft calls mainstream support. Such a support typically runs for five years after a product is released or two years after the successor product is released, whichever is longer.

Delays in Vista and the Longhorn Server have forced Microsoft to extend mainstream support on Windows XP and Windows Server 2003. After mainstream support ends, Microsoft offers extended paid support for five years on business and developer products, but not for its Microsoft Dynamics products.

This year Microsoft will end support for tax and regulatory updates for Small Business Server 7.5 and on Aug. 1 the tax and regulatory updates for all databases will disappear for Great Plains 7.5. In October, Mobile Information Server 2001 and Visual FoxPro 7.0 will see their support disappear, along with Solomon 5.5 and Navision 3.7, introduced just three years ago.

Those applications, which don't qualify for extended support and were brought under the Microsoft banner via acquisition, are being transitioned into the company's product life cycle system.