Microsoft (finally) broadens Windows Vista virtualization rules

Microsoft has lifted its ban on enabling Windows Vista Home Basic and Home Premium in virtual machine environments.

The company announced on January 21 its decision to add the two new SKUs and planned to update its end-user license agreement to reflect the change.

(Microsoft was planning on making the announcement at 12:01 a.m. on January 22, but another publication broke the embargo, so the company is going out with the news early.)

Microsoft almost announced in June, 2007, that it was relaxing some of its virtualization rules for Windows Vista, in order to allow users of a wider number of Vista SKUs to make use of virtualization technology on the desktop. Then, in the eleventh hour, something happened -- exactly what still remains unclear -- and Microsoft ended up halting the planned virtualization changes.

For businesses, Microsoft is offering an annual subscription to what it's calling the "Windows Vista Enterprise Centralized Desktop" for $23 per desktop for clients covered by Software Assurance. This offering, which allows customers to run Vista virtually as a server, previously was priced at $78 per desktop, according to company officials.

Microsoft also announced it has acquired Calista Technologies, a San Jose, Calif.-based desktop-virtualization specialist, for an undisclosed amount. Here's Microsoft's description of what Calist's software does:

"Calista software improves the user experience of 3-D and multimedia delivery for Microsoft multimedia applications, virtualized desktop deployments, and server-hosted virtualized desktops or applications using Windows Server Terminal Services. The addition of Calista technology to Microsoft’s virtualization portfolio will enable people to watch video and listen to audio, and will enable remote workers to receive a full-fidelity Windows desktop experience without the need for high-end desktop hardware. "

("Application delivery" expert Brian Madden provided more details on Calista and how its technology could dovetail with Microsoft's in a prescient post last November.)

Microsoft is planning to announce these virtualization changes at a two-day Virtualization Deployment Summit for about 300 of its customers, which kicks off on January 21.

Until today, Microsoft’s end-user license agreement stipulated that users could run only the Business and Ultimate versions of Vista in virtual machines from Microsoft and other vendors. Microsoft attributed the original Vista virtualization restrictions to potential security risks, claiming that “security researchers have shown hardware virtualization technology to be exploitable by malware” and claimed Vista required an advanced level of know-how to thwart such virtualization exploits.

Any thought on Microsoft's client-side virtualization changes? More to come on this story as it unfolds....

More updates from Microsoft:

* Microsoft isn't ready to talk specifics about how/when it plans to add the Calista technology to its products. But company officials are characterizing Calista's technology as something Microsoft sees as a "platform technology" which it plans to make "as widely available as possible." Perhaps we'll see it folded into Windows 7 ....

* Why has Microsoft decided to add support for Home Basic and Home Premium now? Officials said on Monday that Microsoft is seeing "a maturity in the industry," in terms of being able to trust "what's under the virtual machine." But it doesn't hurt, either, that adding Home Basic and Home Premium will help users run older applications that software vendors are not updating to support Vista.

* While Microsoft did add its consumer Vista SKUs (Home Basic and Home Premium) to the list of products it will allow users to run in virtualized environments, the company is not allowing for the virtualized use of information-rights management, digital-rights management and BitLocker encryption. (These were among the other licensing changes Microsoft contemplated making last June and pulled at the last minute.)

Update to the updates (on January 22): Contrary to what I was told yesterday, Microsoft is now saying that it is not prohibiting the virtualized use of information-rights management, digital-rights management and BitLocker encryption. From a corporate spokesman: "The EULA (End User License Agreement) advises against using these technologies for security reasons, but does not prohibit their use."