no offense, but something about the way you've phrased your question makes me think that you might be confusing the "Emulator" software with RSLogix5 - which is the software needed to program a PLC-5 system ...
specific question: do you already have a working copy of RSLogix5 available? ... if you don't, then the Emulator isn't probably going to do you much good - since you'll need a copy of RSLogix5 to program the Emulator ...
basic idea: the Emulator is a software package that you run on your personal computer - to make the computer "pretend" that it's an actual PLC ...
suggestion: tell us everything that you have on hand - and what you're trying to accomplish ... we'll be glad to help you put the pieces of the puzzle together ...