Could be 1, could be 0, definitely won't be >1 in any one directory, but quite likely >1 if you search the whole machine.
Pretty likely to be a good name in this case, since most people will install Windows before the name is used by something else; but a quick check is good insurance. (And you don't have to bookmark this thread to remember "how to spell it" next time.) Knowing how to look is the good thing.