More Windows 7 XP Mode questions and more Microsoft answers

Over the past few days -- since word of Windows XP Mode and Windows Virtual PC went public -- Microsoft has provided so far only the barest of details about its planned Virtual XP Mode functionality for Windows 7. Slowly but surely the company has started releasing additional details.

I had a chance to ask Scott Woodgate, director of Desktop Virtualization and Microsoft Desktop Optimization Pack (MDOP), a few questions about the new Virtual XP virtualization service. Here's a transcript of our email exchange:

MJF: Will  the new Virtual XP mode be available to Software Assurance licensees only? Which Win 7 SKUs will it be available for when it goes final?

Woodgate: Windows XP Mode is an optional feature (ie. Customers can choose to use it or not) that is available as part of  Windows 7 Professional and above. Windows XP Mode is best experienced on a new PC from an OEM, but will also be available to retail customers. Specifically, Windows XP mode does not require Software Assurance.

MJF: When will the beta begin? Public or private?

Woodgate: The beta begins on April 30 for to MSDN and TechNet subscribers, and broader availability begins May 5. MJF: When is the final product slated to ship? Will it be an add-on to Win 7 final that is downloadable if and when users want it (like the Windows Live Essentials)?

Woodgate: We are targeting Windows 7 GA (General Availability) for the final ship date while also recognizing that we are just entering beta of the product and we want to be receptive to feedback we may receive from beta testers.  We expect small businesses will mostly experience this feature on new PCs but it will be also available through download to Windows 7 Professional and above customers.

MJF: Will Virtual XP also work with Vista? If so, which SKUs? Will it be available for Vista in the same timeframe as for Win 7?

Woodgate: Windows XP Mode is a feature of Windows 7 Professional, Ultimate, Enterprise.  It isn’t available for Windows Vista. Specifically, Software Assurance customers of Windows Vista are able to run this scenario due to the 4 VM (virtual machine) right in Software Assurance. MJF: What are the differences between Virtual XP and MED-V? Will MS continue to offer MED-V as part of a paid MDOP once Virtual XP ships? If so, why would biz users want MED-V vs. Virtual XP?

Woodgate: Top-level answer:

* Windows XP Mode is designed to support SMB customers who do not use management infrastructure and need to run Windows XP applications on their windows 7 desktops.

* MED-V is designed for larger organizations who use management infrastructure and need to deploy a virtual Windows XP environment  on Windows Vista or Windows 7 desktops.

Detail:

* Windows XP Mode is specifically designed to help small businesses users to run their Windows XP applications on their Windows 7 desktop.

* Windows XP Mode is available as part of Windows 7 Professional and Windows 7 Ultimate.

* Windows Virtual PC will enable users to launch many older applications seamlessly in a virtual Windows XP environment from the Windows 7 start menu

* Windows Virtual PC includes support for USB devices and is based on a new core that includes multi-threading support

* Windows XP Mode is best experienced on new PCs from OEMs but will also be available for customers as a separate download.

* Microsoft Enterprise Desktop Virtualization (MED-V) is designed for IT Professionals.

* MED-V enables Virtual PC deployment in larger organizations

* MED-V provides important centralized management, policy-based provisioning and virtual image delivery to reduce the cost of Virtual PC deployment.

* MED-V is part of the Microsoft Desktop Optimization Pack (MDOP)

* MED-V v1 builds on Microsoft Virtual PC 2007 to help enterprises with their upgrade to Windows Vista when applications are not yet compatible.

* MED-V v2 will add support for enterprises upgrading to Windows 7 (both 32 bit and 64bit) and will support Windows Virtual PC on Windows 7.

* MED-V v2 beta will be available within 90 days of Windows 7 GA.

MJF: Why didn't MS just release Hyper-V for Windows 7 instead of doing Virtual XP? What are the differences between Hyper-V and Virtual XP? Woodgate: Windows Virtual PC is better suited to mainstream desktop virtualization users in the application compatibility scenario than type I hypervisors such as Hyper-V. This is probably counter-intuitive because on servers type I hypervisors are better than type II hypervisors (Windows Virtual PC) so let me explain:

Servers typically run virtualization for their entire work-life.  Their job is typically to run virtualization workloads. In that context a type I hypervisor that is running on the system the whole time is fine because although it uses system resources it improves the overall experience delivered by the server.

Unlike servers, people using desktops with Windows XP mode likely use applications for a period of time and then stop using them as they use native Windows 7 applications. For example, I use my older accounting application once a month, a week, or a day and that requires Windows XP Mode but then I close it and work on something else.

Unfortunately Type I hypervisors have performance implications and user experience implications to the PC that exist even when you aren’t using them. For example battery-life might be impacted as well as performance, user experience, and memory usage even if the user never actually runs a virtualized application. In contrast Windows Virtual PC takes resources when it is turned on and takes no resources when it is turned off. This means that the overall PC experience for mainstream desktop virtualization use-cases is better with Windows Virtual PC than with Type I hypervisors given the technology available today. MJF: Will Virtual PC 7 be available independently of Virtual XP? Or are the two only available hand-in-hand?

Woodgate: Customers can use Windows Virtual PC independently of Windows XP Mode.  We expect developers and IT Professionals to do this, as they do today, and we catered to these folks by adding the commonly requested support for USB to Windows Virtual PC.

MJF: What kinds of XP apps are not designated as "suitable" and unlikely to work on Win 7 with Virtual XP?

Woodgate: Older productivity applications that might be used by small businesses are best suited.  Windows XP Mode is not designed for more consumer centric applications such as 3d games, media intensive applications or applications with hardware requirements such as tv tuners. MJF: What are the differences between Virtual XP and VMWare Workstation?

Woodgate: Our focus in this release is on the small business and on simplicity of user experience for application compatibility.

Readers: What else do you want to know about these new features that I didn't ask?