: Ensure you have enough disk space (at least 55 GB for the game, plus space for the RAR files).

The file is typically one segment of a multi-part compressed archive used for distributing the PC version of Forza Horizon 3 . Because the game files are roughly 55–60 GB , they are often split into smaller parts (e.g., 2 GB or 5 GB each) to make downloading more manageable and less prone to total failure if a connection drops. Understanding Multi-Part RAR Files

: Part 5 cannot be used on its own. It contains a specific "chunk" of the game's data. To successfully access the contents, you must have all parts (part01, part02, etc.) in the same folder.