There are a couple of gotchas to be aware of, whether you’re running Windows XP Mode or VirtualBox and a licensed copy of Windows XP.
First, there’s the issue of keeping two different operating systems updated: the host OS and the virtual machine OS. It’s not that big a deal for a handful of users, but multiply it by 50, 100, or more, and you’ve got a support challenge in a business environment.
The second problem is hardware support, including drivers. Standard stuff, like USB memory keys, optical drives, and so on, work fine. But anything exotic could be problematic. We’ve already mentioned the issues with VirtualBox and 3D, for example. We've already seen Parallels enable access to multiple GPUs in a Xeon 5500-series system with Workstation 4.0 Extreme, but this functionality is limited to a handful of HP workstations and not yet available on the desktop.
Given the issues, why would a home or small office want to run something like Windows XP Mode?
One main reason is security. For example, a shared family PC means that the kids are using Web browsers and surfing the wilds of the Internet. Even if you’re running robust anti-virus software and firewalls, it’s all too easy to accidentally download a Trojan or other nasty malware. The solution: encapsulate all the browsers using Windows XP Mode. The user experience will be pretty transparent, and the virtual machine adds another layer of protection.
The other reason is the whole issue of legacy apps. Small businesses often rely on software written on aging applications, whose providers may even be out of business. That leaves them stuck running on hardware that’s obsolete, and parts can sometimes be hard to find. Running XP Mode allows the company to update their hardware, but still run their old apps.
If the main objective is running older apps, then performance won’t really be an issue. Any modern system capable of running Windows 7 will run older apps in Windows XP Mode, and probably run them better than the old hardware. The key pitfall will likely be drivers for custom hardware. We’ve run into problems with new motherboards where the application required data collection through a parallel printer port, and many systems no longer ship with parallel ports. For the most part, however, XP Mode should serve nicely.
VirtualBox is a good fit if the user is fairly sophisticated and wants to run a variety of different operating systems. You can easily run Linux inside of Windows, Windows in Linux, and DOS inside any OS. For everyday users with older apps or wanting an added bit of security, Windows XP Mode is likely to fit the bill. But be aware that you’ll be supporting more than one operating system.