It could become more costly for customers who have older versions of certain Microsoft software to continue purchasing support from the vendor.Microsoft on Monday revised its Custom Support Agreement (CSA) program, which extends support for legacy products that business customers continue to have in their IT environments even after the typical support lifecycle of 10 years expires. According to the changes, Microsoft will no longer put an end date on CSAs, but will allow customers to have them as long as they continue to use some of its legacy products. Due to a new per-device pricing structure\u2014a change from the former flat-fee structure\u2014pricing could become more expensive for some customers that have many servers or desktops running a particular legacy product, said Ines Vargas, director of support policy at Microsoft. On the flip side, customers that don\u2019t have a lot of hardware devices running legacy Microsoft software could save money with the pricing changes, she said.Products affected by the changes include Windows NT 4, Exchange Server 5.5 and Windows XP SP1. Windows NT 4 will be entering its fourth year of CSA support in January 2007, while Exchange 5.5 will be entering its second year of CSA support at the same time. Windows XP SP1 will enter its first year of CSA support in October 2006.Microsoft started the CSA program two years ago to extend the support of its products beyond its regular support lifecycle policy. Microsoft typically gives customers five years of Mainstream Support, while giving business customers the option of purchasing Extended Support for five more years after Mainstream Support expires.Microsoft will make CSA pricing available for the next three years to customers who take part in the program so they can budget for support if they plan to continue having legacy products in their IT environments, Vargas said. Previously, customers knew only for about a year how much they would pay for support through the CSA program, she said. "This is all about providing customers with choices and to [help] the planning and budgeting process," she said. "Large customers are doing planning on a multiyear basis, and the lack of multiyear pricing didn\u2019t allow them to plan [for support costs]."Microsoft does not publicly disclose the pricing for its CSA program, but Vargas said pricing does go up each year to keep up with growing support costs for older software. Only customers with Microsoft Premier Support\u2014its high-end managed support offering for large enterprise customers\u2014can take part in the CSA program, she added.Vargas said she does not believe making changes to the CSA program will drive customers to migrate to more current versions of legacy software, even if it means paying more to support older products. "Customers are already migrating at their own speed," she said. "[CSA] hasn\u2019t driven migrations in the past, so we don\u2019t see why [changing it] would do so now."-Elizabeth Montalbano, IDG News Service (San Francisco Bureau)This article is posted on our Microsoft Informer page.\u00a0For more news on the Redmond, Wash.-based powerhouse, keep checking in.Check out our CIO News Alerts and Tech Informer pages for more updated news coverage.