In the latest sign that computer makers are bucking Microsoft's decision to retire Windows XP at the end of June, Lenovo says it will make the operating system available to business customers until Jan. 31, 2009.

"For a limited time Lenovo is providing Windows XP Recovery CD media as a way to downgrade from Windows Vista," the vendor says in a note currently posted on its Web site.

On Thursday, InformationWeek reported that Dell plans to make XP available until 2010, when Microsoft is expected to roll out Vista successor Windows 7.

Hewlett-Packard also will provide Windows XP to business customers that want to downgrade from Vista after June 30, but the company has not said how long it expects to operate the program.

Lenovo said its downgrade program includes notebooks and desktop computers purchased with either the Business or Ultimate versions of Vista pre-installed.

Dell will include Windows XP Professional as a pre-installed option on its OptiPlex desktops and Precision workstations and Latitude notebooks for at least the next 20 months, according to a Dell employee with knowledge of the computer maker's plans.

Dell's official position is that it will offer the downgrade program "for as long as Microsoft supports it," a company spokeswoman said Friday.

Dell will also make XP available on its Vostro and XPS gaming systems for a small fee after June 30, the date at which Microsoft has said it will no longer make the OS available to large system builders. Microsoft will continue to distribute Windows XP to independent vendors until 2009 and to manufacturers of low-cost systems incapable of running Vista until 2010.

The decision by the industry's three largest computer makers to pull an end-run around Microsoft's Windows XP timetable reflects widespread disappointment with Windows Vista.

Dell, Lenovo, and HP apparently believe that a considerable portion of their business customers are not willing to upgrade to Vista, despite the fact that the OS has now been available for more than a year and has been fully updated with Service Pack 1.

Many business users have complained about Vista's resource requirements, intrusive security features, and lack of compatibility with older systems and applications.

On Thursday, Microsoft CEO Steve Ballmer, speaking at an event in Belgium, hinted that Microsoft might extend XP's life if there's sufficient customer demand.