Microsoft has released the last update for Windows 2000 before it ceases officially to support the server operating system later this week.

The Update Rollup contains 446 upgrades to the software as well as all security updates published since the release of Service Pack 4 in 2003. 

Peter Houston, Microsoft's senior director of Windows Serviceability Strategy, told vnunet.com that at just 32MB, the update is significantly smaller than the average service pack.

A regular service pack holds 1,500 to 2,000 updates. By limiting the number of updates in the Rollup, users will require less testing of their systems, according to Microsoft.

"Every update that we throw in has the potential to disrupt somebody's installation," said Houston.

"Narrowing the number of fixes to just the ones that we know are broadly applicable makes it much easier for us to test and deploy, and minimise the potential for disruption to those systems."

The fixes in the Update Rollup are mostly a selection of the most popular 'hotfixes', updates that Microsoft created for specific users to address specific problems.

Because they deal primarily with problems that do not affect large numbers of users, the patches are not routinely made available.

The included hotfixes are expanded to form general updates for Windows 2000 and were tested accordingly. They were selected because they address security and other common problems, or make it easier to manage the software, according to Houston.

The Update Rollup is the last that users can expect from Microsoft for Windows 2000. After 30 June the operating system will move to 'extended support', meaning that the vendor will address only security issues for the next five years.

"This is designed to help customers that plan to keep running Windows 2000 stay secure," said Houston. "We expect that there will be customers running Windows 2000 for quite a while."

Despite the looming end of support, Windows 2000 remains one of the most widely deployed operating systems in corporate IT environments. A recent survey from AssetMetrix Research Labs found that the software had a 48 per cent market share in the first quarter of 2005. 

Users should not perceive the Rollup as a necessary update for Windows 2000, warned Michael Cherry, an analyst with Directions on Microsoft. Anyone running the software with Service Pack 4 has a stable and secure version.

Microsoft ranks the update as 'high priority' and lists the file in the 'critical and service packs' category.

For users who are reluctant to replace Windows 2000, the Rollup will provide assurance that they can safely stay with their current software.

"It may make them comfortable with Windows 2000 as opposed to migrating to Windows 2003," said Cherry.

The Rollup file is available for download from Microsoft's website or through the Windows Update service.