Download the Samurai WTF (Web Testing Framework) and create a Live CD boot
You can download the iso or the vmware version, depending on how you want to run it. You can put it on a USB stick or whatever you want to do.
Samurai is based on Ubuntu Linux, so it is stable.
We are going to be using Samurai extensively the rest of the semester, so you need to be able to run it reliably somewhere (or everywhere).