Test Center: A cure for Vista's compatibility blues

Microsoft Enterprise Desktop Virtualization, or MED-V, is the productized version of technology the company obtained through its acquisition of Kidaro in 2007. Slated to ship in the second quarter as part of the Microsoft Desktop Optimization Pack (MDOP) 2009, MED-V provides customers who subscribe to Microsoft's Software Assurance program with a means to integrate legacy Windows applications with the current generation of Vista-based desktop operating systems, including Windows 7.

MED-V accomplishes this by enhancing and extending the virtual machine environment of the company's Virtual PC 2007 product. On the server side, MED-V provides a set of centralized VM image management tools as well as tight integration with Microsoft Active Directory. On the client side, MED-V adds various layers of centrally manageable end-user access controls and authentication mechanisms, plus the capability to run virtualized guest OS applications seamlessly alongside native executables.

[ VMwareWorkstation is the Test Center's 2009 Technology of the Year award winner for desktop virtualization. See "Virtualization showdown: VMware Workstation vs. Sun xVM VirtualBox. " ]

When I first reviewed MED-V's predecessor, Kidaro Managed Workspace, I found the product to be a compelling solution that could mitigate some of the more common deployment hurdles associated with virtual desktop technology. Since the acquisition, Microsoft has dropped the product's support for VMware images (Kidaro originally supported both Microsoft and VMware VM formats) and refocused the product on delivering legacy application compatibility services to Windows Vista clients.

Virtual PC inside

This latter point is evidenced by the limited selection of guest OS images supported: Windows XP with Service Pack 2 or 3, or Windows 2000 with Service Pack 4. I expect this list will grow to include Windows Vista somewhere down the road, but for now such a configuration isn't supported. Nor does MED-V support any 64-bit guest configurations, a product of its reliance on the anemic, 32-bit-only Virtual PC 2007 as its underlying VM environment.

In fact, if there's an Achilles' heel to MED-V, it's the Virtual PC engine running behind the scenes. Slow and buggy, Virtual PC is unsuitable for all but the lightest of application workloads. It's also a bit dated in the hardware emulation department, with no support for multiple CPUs or even USB devices. This, in turn, can limit a virtualized application's integration with the host OS: If the application can't see that USB-connected drive or dongle, then it may not be able to function properly or, in extreme cases, to run at all. With the Kidaro Managed Workspace product, you had the option of using VMware's more capable runtime engine to host your images. Now that this capability is gone in MED-V, the overall usefulness of the solution has been significantly diminished.

Still, if your needs are modest -- running a legacy accounting package or providing virtualized access to a previous version of Microsoft Office -- then MED-V fits the bill. And regardless of which runtime engine Microsoft uses, MED-V still delivers the rest of what made the Kidaro product so compelling, including the much lauded Trim Transfer technology.