Shell scripting in windows is substantially different from linux - the syntax is pretty much completely different, and cmd.exe is simply a totally different environment than bash, csh or ksh. I'd expect your exam to be about unix/linux shell scripting, not cmd.exe.
If you want to get close, cygwin might do the trick; it provides a basic UNIX layer for windows, giving you most of the UNIX command line's functionality. It's still not the real thing though; also, downloading and burning a live CD and booting it is less of a hassle than installing cygwin (and getting it to work properly).
I'm also curious how your partition table can be damaged in a way that prevents you from installing Linux, yet allows you to boot into XP flawlessly.