Well, to change themes, (by default) right click your desktop, Litestep >> Change Themes >> and pick what you want. If for some reason that doesn't work, then go in to the "Theme" folder in the litestep directory and open the themeselect.rc. Change the path to a known working theme, like ThemeDir "$ThemesDir$austerity" and recycle (ctrl+alt press R). If none of that helps, be more specific about your problem.

Btw, I predict a thread being moved to a different forum. :D