Just a suggestion. Try to 'ctrl,alt,del' then check your applications and tasks menus, do you see litestep.exe? If so it is installed. Maybe you moved some files by accident? If you want to go back to 'Explorer.exe' (windows default shell) then terminate litestep.exe though the tasks menu (ctrl, alt , del) after litestep terminates restart your computer. "ctrl , alt , del " then click on 'shutdown' then 'restart'. When windows restarts remember to hit "F8" to load to 'Safe Mode' When you load to safe mode it will load 'explorer.exe' by default. See If you can now uninstall litestep. Then if you can, after you do, reboot your computer again, and then try to reinstall litestep. Make sure your computer us up to date will all updates and patches first.
Hope this helps. I had problem like this before. For me to solve it I had to let litestep to install into its default directory.