: If you are using a recent version of WinRAR and need to explicitly join files, you can go to the File menu and select Combine Archive , then select the first split file in the dialog box. Tools and Resources

If you are prompted for a password during extraction, you must obtain it from the original source of the file, as RAR archives can be password protected for security.

Are there to this file (like part2, part3), or is it a single archive you're having trouble opening?

: You can find visual walkthroughs on joining multiple RAR files on YouTube .