I can see in this screenshot you have succesfully downloaded the game and then attempted to download it a 2nd time. You will need a program to open RAR files though, I recommend the free 7-zip program. You can download it here, just download and run the first option on the download page:
https://7-zip.org/download.html
After you install 7-zip you should be able to open the downloaded RAR file with the game no problems.