In a pair of postings to company blogs, Microsoft announced the availability of the single service pack that will update not only , but also , the company's corresponding server software. This is the first time that Microsoft has packaged one download that applies to both the client and server editions of the operating system.

As of Tuesday, subscribers to TechNet and the Microsoft Developer Network (MSDN) can download the beta of Vista SP2 and Windows Server 2008 SP2, , vice president of Windows product management, said in an entry to the Windows Vista blog Tuesday.

Others will have to , Nash continued. "Beginning Thursday Dec. 4, we will be making the Windows Vista and Windows Server 2008 Service Pack 2 Beta available to everyone through a Customer Preview Program (CPP)," he said.

According to a , the Vista and Server 2008 SP2 betas will be available Thursday to the public via downloads over Windows Update, Microsoft's default update service. Links to downloads of stand-alone installers and disk images will also be added Thursday to both TechNet and MSDN.

As is the company's practice, Microsoft discouraged most users from trying out the beta. "The CPP is intended for technology enthusiasts, developers, and IT pros who would like to test Service Pack 2 in their environments and with their applications prior to final release," Nash said. "For most customers, our best advice would be to wait until the final release prior to installing this service pack."