Virtual insanity

Whether you’re a web developer or just an enthusiast, you might like to have multiple versions of Internet Explorer installed for testing purposes. The problem is that installing any given version of IE uninstalls other versions. So what are you supposed to do, maintain a fleet of PCs with different versions of IE installed on each? In a manner of speaking, yes.

A nifty new incarnation of the popular Windows Virtual PC software is now freely available to most versions of Windows 7, which gives you the ability to install virtualized operating systems on your computer, including Windows XP. In fact, a fully-licensed virtual copy of XP, called XP Mode, is available to Windows 7 users for backward compatibility with legacy programs that don’t play well with the newer OS.

Setting up Virtual PC and XP Mode can be a little tricky. For starters, your host PC must support hardware-assisted virtualization (HAV) to use XP Mode. This should be a piece of cake for most newer machines, but you may have to manually enable it in the system BIOS. If you’re unsure whether your older rig supports HAV, Microsoft provides a tool to help you. Once you’ve passed the test, you can proceed to select and install the right version of WPC, and then grab a copy of the XP Mode image from Microsoft’s site.

Using Virtual PC is like having a computer within your computer: the virtual desktop runs in a window, or it can be configured to run full-screen. For all intents and purposes, the VPC thinks it’s a real computer. It even shows up as a node on your network and can be added to your company’s domain. The VPC can even piggyback on the host’s network connection to surf the web and share files with your host PC.

Since it runs within a host OS, a virtual machine (VM) is actually just a collection of files that are loaded within the VPC program. There’s a VM file, which represents the computer’s hardware, and a virtual hard disk (VHD) that holds all of the computer’s data.

Virtualization is nothing new; I’ve been using it for almost a decade. It’s a great solution for testing and training, because if you screw up something, you can just blow out the virtual hard disk and start over. Plus it allows you to build multiple configurations without having to maintain a fleet of physical hardware. Just load up the VM that you need for a given job, and you’re good to go. I wouldn’t recommend it for programs that tax the resources of the host OS, such as multimedia and games, but with enough processing power and RAM, I suppose anything is possible. What’s particularly interesting about this incarnation is how VPC integrates with the host OS.

Once you’ve installed XP Mode, you can easily drag programs to the Start menu of the All Users folder (C:Documents and SettingsAll UsersStart Menu in XP Mode) on the VM, and a feature called Auto Publish makes those programs accessible directly from the Start menu on the host OS, without having to separately launch the VM. Published virtual applications appear on the host’s Start menu under Auto Publish works with any virtual version of XP SP3 or later (including Vista and 7), but you have to install a separate update on the VM to make it work (the update is pre-installed on the XP Mode VHD).

Back to my point about running multiple versions of IE on one computer. Windows XP ships with IE6 by default, so once you have XP Mode up and running, you’ve essentially got IE6 available on your host computer. Simply copy its shortcut into the virtual All Users’ Start menu. Voila! You’ve got IE6 running in parallel with other versions of IE, right there on your desktop.

By the way, this works equally well for other “exclusive” apps that might not otherwise coexist peacefully on the same machine, such as different versions of Outlook.

As you can see from the screenshots, published applications run right on the desktop of the host, including the window chrome of the guest OS. Once you overcome the shock of seeing Fisher-Price windows floating around on your sleek and sexy Win 7 desktop, it’s quite natural to use. I promise.

– Greg