Hey Ray,
(Geez, sounds like the Van Halen tune...)
Still almost sober enough to see your post.
Unless the rar file is way big, Winzip will open it. Can always download Winrar. The program can deal with problematic rar files that escape Winzip.
Problem may be a corrupted download however, most likely the cause if you are having trouble opening it.
Redownload the file. Hit it with Winzip or Winrar again.
Note that Kenny's file is using Piano One as a placeholder to illustrate a function. No link from the tutorial to the hands on trial, so any generic piano or vsti will do fine for the sake of learning, example and following along..
John