Anything you break with a litestep theme is always totally fixable. If your worried about tweaking litestep to the point that you can't load anything, get a shell-select tool (carapace is available at http://www.lowdimension.net and is my choice).

It lets you select any shell you have installed (ie explorer and litestep for you?) when you boot up your computer, so if you totally screw up litestep, you can just reboot, get into explorer, and fix litestep.

There are also better failsafe methods, ctrl-alt-f1 brings up a mini popup with important features like kill litestep, restart, etc. Plus win2k and winxp have the nice task manager if you ctrl-alt-delete

You shouldn't need to back anything up at all.