Do you have Winrar or 7-zip installed? You need one of the two to open an .rar file. I suggest 7-zip, winrar has a annoying pop up after an "trial period," which you can still use after the period.
Winrar is not safe to download for most window pcs. It can seriously screw with the computer and you'll have to reset everything to fix it. I had to learn that the hard way wen I tried it last time.
here's a tip: when you use an installer from a sketchy website, don't just repeatedly click next like an idiot. pay attention to what the installer is actually doing.
