Overall, I like Virtual PC. It's easy to whip up generic enough Virtual PCs that run with many of the oddball tools a security researcher needs to try out. The controls are elemental.
And that's also its main limitation: It's a bit elemental. There's no built-in support for Linux in the Additions package that improves performance. The templates have no support for trying out Vista, the next great version of Windows. Something as basic as USB drive support in the virtual instance is implemented with shared drives—and these only in DOS, Windows, and OS/2 Virtual PCs. (OS/2? Let the dinosaur die, please!)
But before you get out the money for VMware, understand that it offers a lot of features, but they work with mixed results. Sure, there's a template for Vista, but it doesn't work with Vista 5308. Yes, there's great Linux support, but not for something as generic as DSL. And with all of those abilities comes a dizzying array of knobs, features, and configurations to twist and turn into a working machine. That sort of unpredictability and specialized configuration tuning seems to hurt research. Was the effect truly representative of what will happen on common PCs?
In contrast to VMware's behavior, Virtual PC lets me do a majority of what I need to do—in just minutes. Testing on physical PCs shows high predictability. But I haven't been able to run Vista on it for some time, and even then it was slow. Imagine having the dual virtual-processor abilities that VMware advertises. No matter—Vista won't run on it as well without blue-screening the installation. Maybe it's something with my portable and its dual core? Maybe 1.25GB RAM isn't enough? Maybe going with a tool that's easier to diagnose is better?
Ultimately, the decision is yours. Overall, my experiences with Virtual PC have been very good. Now that Virtual PC Server 2005 R2 will be free, I think that the server versions of these tools will make for a good follow-up article. To do that, you'll need to indicate your interest in the comments below, and I'll need to max out the RAM in my test PC. Until then, I can't wait to remove VMware and its services that run at system startup, whether I run an instance or not. I should have known that this product would consume resources in a big way, when the installation required a reboot!
Meanwhile, here's hoping that Virtual PC comes out with an easier cloning process, support for Vista, and a few other goodies. It has a lot going for it now and can only get better.