You don't need to open Winar, just download it and you should be fine. You do not need to pay for Winrar even if your free trial expires. Once you have it downloaded, do the following:
- Create a new folder on your Pc, you can name it whatever you like and put it wherever you like
- Download the game from this website and place it in the folder you created
- Right click the game file and click extract here and wait until all the files appear in your folder.
- Lastly, find the file "AtC_BB" and double click it. and you should be able to play