Linux
I tried three versions of Linux: Mandrake, Fedora and a curiosity called "Damn Small Linux". Microsoft does not make any claim to support Linux or not, but in fact Virtual PC 2004's support for Linux is superb. The only issue that I haven't solved yet for the various distributions is setting up the virtual soundcard; but this is more of an issue with Linux that with Virtual PC. I will post solutions for versions of Linux as I find them. Both Mandrake and Red Hat came with a really comprehensive list of programs for free that would cost thousands of dollars in the Windows world. OpenOffice.org is a polished office suite, Mozilla and Konqueror are both first-rate web browsers, and The Gimp is a stunning challenge to Photoshop. For a home office for the more technically inclined, these Linux distributions may well provide all you need. Linux does necessitate a higher learning curve and so may turn off less skilled users (or even skilled-but-lazy users like me); also although the programs are fantastic and the KDE shell is a great desktop, they do fall a little (only a little) short of the polish of Windows XP. Also there aren't really any good games. Fortunately Microsoft itself is providing a tool that can provide the fun of a theme-park rollercoaster: you can explore the depths and feel the thrill of Linux, while remaining perfectly safe in your Windows environment. In general the performance of Linux under Virtual PC was very good, the only limiting problem involved demanding graphics applications. See the Downloads & Links page for information on obtaining Mandrake, Fedora and other Linux distributions. MandrakeI downloaded the latest distribution of Mandrake 10 from their website. Of course the download took forever, but I then had the necessary ISO images. Linux can be obtained freely -- there are distributions for sale that offer the convenience of a CD's ready-to-go and support. The setup is pretty easy, but if you have more than 512 mb RAM on your host system, consider bumping up the amount of memory available to Linux. Tip: Do not start by allocating too much memory to your Linux setup, this may cause the install to fail! Generally start between 128 mb and 256 mb. You can up the amount of memory later. Next, under the Virtual PC's "CD" menu, select "Capture ISO Image..." if you have a downloaded distribution, or just capture the CD if you have it already on CD. The hit reset (Action->Reset), and let's see what happens... Almost instantly, you will get the Mandrake Linux install screen. Choosing the correct settings is a no-brainer, basically if the installer asks you to do something, you do it. Remember, you are now in a virtual machine, and there is nothing that can go catastrophically wrong -- your desktop is safe. If in doubt, just go with the defaults. Very important:Use the S3 Trio 64 driver and make sure to set your screen to 16 bit color; Mandrake install will default to 24 bit color ("Millions of Colors") and is NOT supported by Virtual PC. You can recover if it is set to 24 bit color, but it is a real pain in the behind. When you run the configuration you will also get the chance to change the amount of video card memory from 4 mb to 8 mb. This will help with higher resolutions. You can also fairly easily change any setting later after Linux has been installed. Also be sure to select "Configure" for the soundcard, and let the installer know you are setting up an "ISA" soundcard. It won't set up the soundcard right away, but will install software for you to do this later. You can set up other aspects of the system here, but everything is pretty automatic. So be sure that when you get to this screen... 
...to change the color settings to this:  |