I believe if you are using Windows and download the USB version of greenfoot to your flashdrive, you should be able to port it to any compatible computer. The USB version of greenfoot comes complete with everything needed (JDK, et al). The book scenarios are not required.

Wait, so I currently have the Greenfoot windows installer and the JDK on my flashdrive. I also have the book scenarios folder (I need it to complete my summer work) in my flashdrive. Would I be able to bring my flashdrive to another computer and be able to run Greenfoot properly?

I am not sure if you are confused or not. If you INSTALLED the USB (Windows version) on your flashdrive, it should run (from the USB) on any computer running with a recent version of Windows (see the documentation for requirements).

Not sure if I am adding to the confusion, but: It sounds like you should be using the "standalone" version of Greenfoot, which is designed to run from a USB stick, but it also sounds like are not doing this and have in fact copied the regular Windows installer plus the JDK to the USB stick: To answer this: If you really have the installer, then you will need to install Greenfoot on the other computer (but after doing that, yes, you should be able to run it; you might need to Browse, when prompted, to the JDK on the flash drive - or do you only have the JDK installer on the flash drive?) Perhaps you should clarify exactly what you have downloaded, and what you have done with it, and what you expect to be able to do. But in general, if you want to be able to run Greenfoot from a USB stick on any (Windows) computer, then you need the "standalone" version of Greenfoot.