For many of us, virtualization is something that is relegated to server cabinets and has no place on our desktops. However, in a couple of recent instances, virtualization has been the easiest answer to some of the oldest problems in computer history: desktop migration and compatibility. I want to go through a couple of scenarios real quick to demonstrate how this awesome technology can help even desktop users.

Scenario 1: Windows XP Machine we want to upgrade to Windows 7

As we should all know, Windows 7 provides many benefits over Windows XP, including a very solid backup solution, increased security, productivity and resilience. Upgrading your Windows XP machines should be a no-brainer. However, a lot of us don't want to have to deal with migrating our programs and documents over to the new machine, and this hurdle has stopped many upgrades before they even begin.

Previously, we could "dual-boot" our systems so that we could go into the old system or the new system. This usually required two hard drives to accomplish the task easily, and migrations could sometimes take months due to the inability to have both systems up at the same time. Plus, the old southern adage: "if it ain't broke, don't fix it" came up a lot. I've even seen situations where an entirely new machine was purchased to make the transition a little easier, but this usually ends up with the old machine running for a while with the new one starting to gather dust bunnies.

Enter virtualization technology and the solution becomes so much easier. In about three steps, you can make your old Windows XP into a virtual PC on your new Windows 7 machine, running both at the same time without the need for extra hardware or hassle. One client, when provided this solution, said:

You were right on the mark with the suggestion to go with the virtual box rather than dual boot. Using the close button to save the virtual machine will be much more practical than having to reboot to XP. All it took was one shut down and restart to settle that issue.

Here's the procedure (taken with some additions from http://www.virtualbox.org/wiki/Migrate_Windows):

1. - You'll need to prepare the Windows XP machine with MergeIDE. This utility is in German, but the usage is very simple. Extract the files in the package to a folder, insert a Windows XP CD into your CD-ROM drive, and run the batch file. That should do it. It's important that you shutdown the XP install after running this tool, and don't reboot it on the physical machine.

2. - If you are installing Windows 7 on a new hard drive, remove the old drive, install the new drive and load Windows. This is by far the easiest thing to do. You'll appreciate the speed boost of a fresh hard drive too!

3. - Once 7 is installed and ready to go, hook up your old drive and download Microsoft's disk2vhd program. Install this and create a VHD of your old Windows XP drive. You can then format your old drive to hold the VHD and keep your main drive from being thrashed by the XP VM.

4. - I recommend using VirtualBox for the actual virtual machine, so download that and install it.

5. - Create a new Virtual Machine that is setup with the VHD of your old drive and make sure that IO-APIC is enabled. Plus, check on 2D and 3D acceleration for a nice performance boost.

6. - The first couple of boots will be rough as XP resets itself for the new virtual hardware, and it will run quite slow until you install the VirtualBox Add-Ons, but once it's done, you should have your old computer running in a window on your new one.

There you have it, run your old computer in a window on your new one with a couple of free utilities and a new hard drive. It's doable without the new drive, as long as you have somewhere to stash the Windows XP VHD, but this method is by far the easier way to go.

Scenario 2: That old software that won't run in Windows 7

One thing that is true of all system OS upgrades is that compatibility with your old programs may be an issue. When Apple went from PowerPC to Intel, they had Rosetta to (slowly) emulate a processor so that your old software would run. Linux users have to recompile software to get it working on newer distributions, and even iPhones have had issues with applications after a system update. Windows 7 introduced a new technology to help out with these issues called "XP Mode."

XP Mode is a fully licensed virtual installation of XP inside your Windows 7 machine using Microsoft's Virtual PC technology. This is great for old software like Quickbooks 2007 or Microsoft Office 2000, just to name a couple.

Simply visit Microsoft's XP Mode website, and they'll walk you through setting everything up. Once the virtual machine is ready to go, simply enter Windows XP Mode and install the software like you normally would. Then log off and you'll see the programs you just installed on your Windows 7 start menu. My Documents is pointed to Windows 7's Documents folder and printers are even shared out, making everything easy.

There are a couple of issues, as there always are, including one that I just found while writing this article. It looks like moving a XP Mode application off of the primary monitor in a multi-monitor setup is not supported. It's a very strange limitation, and hopefully something that will be resolved soon.

Another problem arrives with the sharing of printers. You'll need to make sure that your Windows XP installation has a driver installed for your printer to make it work. This can usually be done by connecting to a shared copy of it over the network, or by installing the manufacturer's package.

Virtualization: It's not just for servers anymore.