If you are working with multi-part archives (like part1.rar ):
Files from "areal-gamer" or similar unofficial sites often carry risks of malware or incomplete data. For a stable experience, verified platforms are always safer. Resident Evil Revelations Depots - SteamDB
The main campaign is single-player only, but the highly replayable Raid Mode supports two-player online co-op. Technical Tips for .rar Files
Use a reliable utility like 7-Zip or WinRAR.