I'm looking for a free unix download(for a p.c. which I think is running xp) to simulate or mirror a unix operating system to teach a friend basic unix skills for an interview. I saw the solaris link, but couldn't really tell if it would work on a p.c. And I don't want to mess with his operating system, I just want it to run in it's own little environment/window so he can practice basic commands(editing files, redirects, creating removing directories, traversing through directories...)

Suggestions???

P.S. Last I checked they were using SUN computers where he will be interviewing, if that makes a difference.