Ensure Crackdown.3.part1.rar , part2.rar , and part3.rar are all in the same folder.
Dealing with multi-part RAR files like can be a bit tricky if you haven't done it before. How to Extract Multi-Part RAR Files Crackdown.3.part3.rar
Download and install a program like WinRAR or 7-Zip . Ensure Crackdown
If you have a file named "part3," it means you have a . You cannot extract it on its own; you need all the parts (Part 1, Part 2, etc.) in the same folder. etc.) in the same folder.