Windows Virtual PC is pretty slick for having virtual machines on a Windows 7 computer. I use it for multiple Linux virtual environments including Backtrack and CentOS on a regular basis. One issue you may run into is that your wireless network card will likely not work in Linux so you will be required to use shared networking (NAT) instead. Below is information on what you will need to do to get shared networking (NAT) operational in Backtrack Linux.
I noticed this error during a deployment of numerous servers that were configured with litespeed, postgreSQL, and ruby. The installation process was to install ruby, install ruby gems, install postgreSQL, install litespeed, and then sync up the web directory using SVN. After doing so connect via a browser to the server to test things out. On one server I was getting a “503 Service Unavailable” error. The lshttpd(litespeed) logs looked like the below example.