Want to use your Windows machine when you don't have it with you, but there's another computer available? Or try some software, documents, or URLs you don't trust to be malware/bug-free on your own production system, without worrying about the productivity toll of creating a restore image, being sure it really works, and potentially doing that re-install?

One of the various possible solutions is to create a Virtual Machine (VM) image of your system's hard drive -- a copy of the OS, applications, configurations, and specified data -- known as a P2V (Physical to Virtual) image, and then run it, as a VM, under one of the many available hypervisors like those from Microsoft, VMware and Oracle. Many hypervisor vendors offer "players" with a limited feature set, suitable for running existing VM images.

The VM player runs as an application alongside other applications, e.g. adjacent to FireFox and Microsoft Office; the virtual machine image running under the player is running the OS that the cloned system had, looking like a copy of the user's original machine.

For many users, P2V cloning of a Windows system's hard drive(s) to a virtual machine image can be a daunting task.

Paragon Software Group recently announced versions for a free version of its Go Virtual program. Free for non-commercial use. Paragon Go Virtual is intended to simplify the P2V process. According to Paragon, the free version (versions, technically -- one for 32-bit Windows, and one for 64-bit) of Go Virtual works with all desktop versions of Windows since Windows 2000.

(Users will have to separate download a virtualization application to run the VM image under -- many free ones are available -- such as Microsoft Virtual PC, VMware Workstation, VMware Fusion, VMware Player or Oracle VirtualBox.)

Why would anyone want to do create and run a P2V VM clone?

Several reasons, according to Paragon: One, to bring your desktop environment -- the version of Windows you're using, along with its configuration and settings; additional applications you've installed; and data -- with you, to run on another computer, as an application, rather than trying to reboot it with your configuration.

The cloned image of your Windows system can also be run on non-Windows machines, as long as there's a corresponding hypervisor or VM "player" (a hypervisor just for running VMs) available, like, on MacOS, Parallels. Paragon is working on support for Xen, according to Koka Sexton, manager of business development, Paragon.

Two, for doing things that might potentially damage your OS and files, compromise security, or simply avoid the hassle of a difficult uninstall, like testing a new application or version, or browsing potentially unsafe web sites. Malware or other threats are confined within the virtual machine, they can't 'escape' onto the host machine, just like Dell KACE's recently-announced free Secure Browser does for a web browsing session. When done, simply terminate the session (after saving any files you've created or updated that you do want to keep, to a location outside the virtual machine.)

Three, to "migrate" to a new machine, or new OS. (Not as the primary OS, but as a way to test out the new hardware and/or software.) And four, to provide a full-system backup which can be run on another machine, rather than needing to be installed or restored.

For example, if you put the player and your P2V image on a USB flash drive, you can run it, and get what acts like your computer, on a computer elsewhere in the company, or at a hotel business center, library, or other facility -- assuming, of course, that this other computer is set to allow applications to run from external media.

"I've been trying Paragon Go Virtual, and it does what's claimed," reports computer/network consultant David Strom. "It is definitely useful, for opening up unknown software and files. The interesting feature that Paragon has in this version is that, unlike with some of the other free tools, you can make some adjustments to your disk image."

The free version of Go Virtual does not allow incremental saves, like changes made to a virtual machine, such as software updates or patches, configuration changes, or additional applications, Sexton notes. These features are available in the Professional version (MSRP $69.95). (However, while the VM is running, you can do backups, like of new data files, to an external drive.

Also, the free version of Go Virtual only works on desktop versions of Windows; Paragon offers a separate version for servers.

"There are around a dozen of P2V tools available, from VMware and other companies, like InstallFree, MokeaFive and ZInstall," says Strom. "Go Virtual does what it says it does, and can be useful, but there are other tools which may better suited to some use cases."

Also, in general, Strom notes, "The biggest limit of these tools is that you need a lot of storage, and a relatively fast network, to move the files. they're usually several gigabytes in size."