IT managers must decide whether to sign a potentially expensive custom support agreement with Microsoft if they want to continue running NT 4 server from 2004 or incur migration and, possibly, licensing costs moving to Windows 2000.
"The majority of the installed user-base across Europe is on NT 4 server. We are concerned that customers may not have the time to migrate," said Microsoft senior marketing manager Lars Ahlgren.
Microsoft would prefer users not to take out a custom support agreement as it had only signed a few such agreements in the past. But Ahlgren said, "We are anticipating many more."
NT 4 server has been available since 1996, so many installations are running in mature, stable environments.
IDC research director Dan Kusnetzky said, "People will continue to run NT 4 until either they stop using their installed NT 4 applications, their company is acquired or it goes out of business."
While Microsoft is, officially, stopping mainstream support at the end of this year, Kusnetzky said businesses with large enough NT 4 installations would still be able to receive support, albeit at considerable cost.
One area where NT 4 server is still widely deployed is in Microsoft Exchange e-mail systems.
A report from Gartner in July estimated that 5%-10% of enterprises using Exchange have completed their migration from Exchange 5.5 on NT 4 server to Exchange 2000 running Windows 2000.
Gartner said the complexity of the migration meant most organisations had to evaluate their options carefully and this resulted in the slow take-up of Exchange 2000 and the Windows 2000 operating system.
Ovum analyst Eric Woods said the next version of Exchange 2003 would target Exchange 5.5 users, providing them with a migration path to a supported Windows server platform and the latest Microsoft e-mail server. A beta release of Exchange 2003 is available from the Microsoft Web site.
To help users migrate from NT 4 server, Microsoft has provided a resource toolkit available from its Web site. Microsoft Windows server marketing manager Mark Tennant encouraged users to download the toolkit and look at the work required to migrate.