Well, I have been running litestep for quite sometime and I always log in to my default name. For kicks, I enabled the guest account (which to this point has been unaltered) and logged in to it. Lo and behold, I logged on and there was explorer. It was as if Litestep weren't even in existence. I also run dvorak (an alternate keyboard layout) and the guest account knew nothing of that either. So, in my experience, it was fine to have different accounts on the same computer, one running litestep and the other explorer. I even did the fast user switching and it worked fine.