I've used WUBI before, but a while ago, and at least for me it worked like a charm. I'm not quite sure what happened with you machine. When you got your copy, downloaded or otherwise, did you check it for errors? (HASH, etc).
Could you tell us a little more about your situation so we can try to help more?
What version of windows xp(home/media/pro...), is this the linux and win 32bit or 64bit, ... Do you have any screenshots/pics?
Is there a chance that you selected the wrong partition when installing?
The '/' I think you are referring to is the root directory. This is the starting point for the user-level file system used by linux (and many others).
Do any of these threads help: http://ohioloco.ubuntuforums.org/sho...d.php?t=576476