In What is this "Linux", anyhow? we mention using Vagrant as a way to quickly configure a Linux virtual machine, and the Raspberry Pi Kernel-o-Matic uses Vagrant to set up a VM for cross-compiling a custom Raspberry Pi kernel.

Vagrant is a software package designed to let you easily create disposable VMs from a library of freely-downloadable images and connect to them, all with a few simple commands in a terminal. The idea is that you can continue to run your desktop OS like Mac OS X or Windows 7 or whatever, but then make a tiny new Linux computer in a window that you can connect to whenever you need to run Linux software

Unfortunately this isn't quite as seamless on Windows machines as on GNU/Linux or OS X systems, but with a few minutes of effort you should be able to do this any time you feel like it:

This is a brief guide to installing the three moving pieces needed to make this work well on a Windows machine:

1. Vagrant itself
2. VirtualBox to run virtual machines
3. msysGit, a Windows distribution of Git and some other Unix tools, for cloning git repositories containing Vagrant configurations and connecting to your new VM with SSH