I like to always have the latest version of iTunes on my machine, but I also need to keep an older version (7.5 or lower) on my machine for compatibility reasons (please don't ask why - I just do). Is it possible to install multiple versions of iTunes on the same PC (using XP and/or Vista)? If this is not possible by simply installing in different folders, I'm guessing that I can use this "virtualization" that I've been hearing about. I've used Parallels on a Macbook before, but what can I use to create a virtual machine on a PC? Is there a free program that does this?