When I got a brand new development machine, a few months ago, it came with Windows Vista as an operating system. On previous older machine I was not too happy running Windows Vista, but this time the story is different. I am running without any problems right now. Using Visual Studio 2008 for Windows Mobile application development simply works. However, at the same time I am involved in developing a larger desktop application, written in C# with Visual Studio 2005 as development environment. Even though side by side installation of Visual Studio 2005 and Visual Studio 2008 is fully supported, I’d rather have one single development environment available, so my Windows Vista machine only has Visual Studio 2008 installed. Also, I like to have exactly the same environment as my co-workers for this desktop project. Therefore, I need a machine that is running Windows XP and has Visual Studio 2005 and SQL Server 2005 installed. Instead of setting up another physical machine, I decided to run install and use Virtual PC on this development machine. I have done so frequently in the past, but also with machines with limited processing power and not too much memory. This time, using a high speed quad core processor and 4 GBytes of memory, things are completely different. The performance of all my virtual machines is excellent; I hardly even realize that I am running on a Virtual PC. Better yet, even when running the Windows CE Device Emulator on a Virtual PC, which in fact is a virtual machine running inside another virtual machine, performance is still acceptable. So now I have separate virtual machines for Windows CE development, for desktop development and one more to test several beta products. If something goes wrong, it is extremely easy to simply create a new Virtual PC, especially when dealing smartly with a virtual base hard drive, containing an operating system and development environment and the latest software updates, and making use of differencing disks to store my own data. I really like virtualization. It allows me to be more productive, run many different programs side by side, and it keeps my physical development machine much more stable. I only have one big wish. It would be absolutely great if my Virtual PC Images could be configured in such a way that I could connect to all kinds of different physical hardware devices.