Buried under all of the clamor and kvetching about Windows 8's most obvious features -- Metro! Metro apps! -- is a new addition that hasn't made a lot of headlines: Windows 8's new Hyper-V-powered virtualization functionality. Oddly, most people don't seem to know Hyper-V even exists in Windows 8, let alone what it's good for. But it's one of the hidden pearls inside the Windows 8 oyster.
The exact technical name for Hyper-V in Windows 8 is Client Hyper-V. Microsoft picked this name to distinguish Windows 8's implementation of Hyper-V from the full-blown Windows Server incarnation, which is aimed at the server market and designed for more upscale, industrial-strength virtualization scenarios. Client Hyper-V is for end-users on the desktop who want to make virtualization work for them directly.
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People may disagree about Windows 8's new surface, pun intended, but there's little arguing that many great things have happened under the hood. Client Hyper-V has started to open up a range of possibilities -- not just for experimentation, but for everyday tasks -- that make Windows 8 a little more appealing to the power user.
An inevitable question is how Client Hyper-V shapes up against stand-alone virtualization platforms such as VMware Workstation and VirtualBox. If you've used either of those apps (or another third-party virtualization product), you'll note that Client Hyper-V offers many of the features they do: support for a broad range of virtualized hardware, snapshotting, dynamic allocation of memory, support for multiple virtual processors, and so on. Plus, Hyper-V should give better performance thanks to its architecture, especially when working with Microsoft operating systems as the guests -- but don't count on it. Your usage scenario and hardware, and thus your mileage, will vary.
The biggest reasons to continue using VMware Workstation or VirtualBox would be your existing investment in expertise and familiarity with them. But it's well worth trying out Client Hyper-V with your existing virtualization projects to see if there's a major boost in performance or if you simply like the Client Hyper-V interface better.
Getting started with Client Hyper-V
What exactly can be done with Client Hyper-V? In fact, there are several ways you put Client Hyper-V to work, ranging from reproducing functionality found in earlier versions of Windows to running operating systems that aren't Windows at all. I'll explore five of the most useful options in this article.
Before we dive in and start provisioning VHDs, Client Hyper-V has a few system requirements and behavioral restrictions you should be aware of. First, Client Hyper-V has stringent hardware requirements. Not every PC will be able to run it. You need a 64-bit processor that can support Second Level Address Translation (SLAT). You also need at least 4GB of RAM. If you're in doubt about your PC, you can run a utility like Coreinfo to find out if SLAT is supported on your machine. Many notebook-edition CPUs do not support SLAT, but most desktop processors do. If you're running the most recent generation of Intel or AMD processors, then you're golden.
Second, Client Hyper-V is not installed by default in Windows 8. In fact, the setup process for Client Hyper-V is a convenient way to determine if the computer you're using can support it in the first place. Search for "features" in the Settings section of Windows 8 Search, and launch "Turn Windows features on or off." There, under Hyper-V, select Hyper-V Platform (and enable all the other management tools). If you don't have the right kind of hardware or if the hardware properties you need are disabled in BIOS, you'll get a warning to that effect.
Finally, when running any instance of an operating system, always make sure you have the right to do so, per the licensing agreements for the software. Copies of Windows must be licensed for use in virtual machines as well as physical ones. The host instance of Windows 8 doesn't automatically give you the right to run guest instances of any version of Windows.