I can´t install it
It's not something you install! With a .rar file, you "unzip" the file and then click on the game icon and viola!
If you're having trouble unzipping the .rar or anything like that; I suggest googling your problem as unfortunately I don't have enough details or knowledge to help you.
Or, if all else fails, look up someone's LP on Youtube! There's plenty around. :D