Microsoft Virtual PC 2004, which has just been released, supports kernel mode debugging via a virtual serial port just like VMWare. For those accustomed to using VMWare with a virtual serial port, setting Virtual PC up should be very straightforward, as the configuration UI is spookily similar. Coincidence? :) Anyway, shops that have an MSDN subscription already can download Virtual PC from MSDN Subscriber Downloads.

When I was at Microsoft in November I talked to the PM of the Virtual PC team, and explained how I use VMWare for testing my kernelmode code. When I asked if they supported inline snapshots I was told no.

Although VirtualPC does now have named pipe support, it can't snapshot inline (while the OS is running in any given state), making testing things a nightmare as you ALWAYS have to reboot. With VMWare I currently have many different images in different states, allowing me to quickly test my code in different scenarios. In on particular example, I have a VMWare image pointing to a driver install where when "resumed" it immediately installs my recompiled driver and within seconds is rebooted. Doing it from power on would take about 2 to 5 minutes for two reboots. At about 30-50 "virtual" reboots a day, I am easily saving 3 to 4 hrs a day of wasted time waiting for the extra reboot if I used VirtualPC. In my first day in time saved I paid for the cost of VMWare. Now thats an ROI!