you will need a software program that will "expand" rar files. They are compression files like zip files, but not all programs will "unzip" them. I use two different types of programs and someone else also mentioned one they use. I really like The extractor 1.4.1. It has lots of extras that work for me. I've attached the download link to CNET if you are interested.
thk you, taking a chance & hv downloaded the Extractor. If I fumble you may hear me yelling for help lol; I hope you'll come a running!
I don't know about RAR, but Joke gave you a reference to an answer about this in her answer, click on it and see if it makes sense to you. Bringing you back to the top. Hugs, Marji